You can get it here – http://www.forgeworld.co.uk/Downloads/Product/PDF/t/Tauupdate.pdf – and highlights include:
1. All the units in it are 40k-legal 
2. Tetra Markerlights are Heavy 4! Tetras come with Marker Beacons, and something called Forward Observer. What is that?
3. Remote Sensor Towers now get TL Markerlights, can grant one unit per Turn re-rolls to hit and have Positional Relays! No more loading up your IC with one of those.
4. The Hammerhead Turrets have all changed, apart from the Fusion turret. They are all cheaper; Burst Cannon turret gets 2x the shots it used to have, Missile Pod turrets gain Blast, but only Assault 2, and Plasma Cannons basically become Ion Cannons, but with +1 shot and TL for the same price as an Ion Cannon. Err, why would you ever take an Ion Cannon?
5. Drone Sentry Turrets are now Troops and 20pts cheaper each! Woohoo. And they come with Marker Beacons for free, meaning they get re-rolls on the deepstrike if a Pathfinder’s Devilfish can see their landing spot.
6. Heavy Gun Drones haven’t changed so far as I can see.
7. The Great Knarlocs are all Monstrous Creatures now
8. Knarloc Riders are -10pts, but lose Fleet. Still failing badly.
9. No TX-42s. At all 
I’ve not got the book to hand, but isn’t Forward Observer the rule from the printed book, that Tetras have to be deployed and can’t be held in reserve, and always get a free move before the game starts? (A bit annoying it’s not in the PDF though).
Tetras and Sensor Towers are suddenly made of win.
The rule in the book is Forward Scouts, which is just a scout move. The Update gives Tetras Scout and Forward Observers. Wonder what it is. And why Forgeworld CBA telling us. Something from the New Codex? I remember when the IA:1 and IA:2 Updates came out, before the new IG Codex arrived, and those contained some terms that appeared in the IG Codex.
Would love to get a game in with some of these soon. Hmm, what could I abuse with the new TL ability of the Sensor Towers?
Units to give TLing to by sitting them within 6″ of a 40pt Sensor Tower:
a. Pathfinders. TL Markerlights
Total cost 240pts for 16 ML shots at BS4 Twin Linked against 4 targets, vs 192pts for 16 ML shots from Pathfinders, hitting at BS3 Twin Linked against 2 targets. And I haven’t included the Devilfish Tax in there. I want Tetras!!!
b. Unit of Fireknives. TL is better than a Targeting Array, so that 40pts pays for itself in less than two Turns.
c. Hammerhead. TL Railguns are not just for Broadsides any more.
d. Tetras. You can have up to 4 in a Team, and with Target Locks each of them can put out 4 Markerlight shots
Note that there is nothing to stop the unit in question further benefiting from any Markerlight Tokens the Tower itself puts on their target.
Note also that there seems to be nothing stopping the enemy from using a Tau Sensor Tower. Hmmm.
The Sensor Tower rule is slightly clumsily worded… you’re right, as written the enemy can benefit by it (though that’s clearly ridiculous, and I think the word “its” is supposed to refer to the Sensor Tower)… but it’s also not clear to me whether each unit within 6″ may use that ability once per turn, or whether the Sensor Tower confers the ability once per turn. One presumes the latter but it’s not clear.
Also I should point out that nowadays cavalry are always Fleet, so Knarloc Riders are just cheaper than they were. Still not very good, but not any worse. (Though no mention of Kroot Rifles not giving them +1 Attack, though… does the previous FAQ still apply?)
My conclusions: Tetras and Sensor Towers have become awesome, Sentry Turrets have become cheap enough to possibly be worth taking, but the rules could have been a lot clearer.
I have to add that the drone towers were open tooped if thy had fired in their last turn, now they are not.
After reading the new rules i would say that these rules gives us, tau players, much more freedom, the possibility of fielding the tau drone turrets with missile pods as a troop enables us to field non railgun units in the heavy suport, for example deep stiking these turrets in the back of the enemy lets us attack their vehicles with S7 shots at their back AV, or field the senties in an objective making a barrier of av12, with 2 groups of 4 you could even try to make a circle of 8cm making impossible to reach the objective whithout destroying some turrets.
IMHO the turrets will let us field more interesting choices in the heavy slot, of course a unite of broadsides for land raiders, but now the hammerhead with plasma cannnon can be easily fielded to anihilate long fangs, or if you feel you can use sniper drones (remember their BS4 markerlight)for a fun match.
The Plasma Cannon Hammerhead is an attractive choice for the points cost, although I cannot really get over anything that isn’t S10 AP1 in the Heavy Support slot!
Agreed that the Drone Sentry Turrets have lots of fun deployment options. Not quite as good as they had before, but OTOH now you can DS the whole unit and still have it count as one unit, which means a single ML token will boost the whole unit to BS3. Those things will have a field day in the opponent’s deployment zone, and with Marker Beacon they will be accurate enough to consider Melta Guns on them.
Itching to get a game with all my new toys
The thing about deep striking the drone turrets, though, is that they’re not very tough, as immobile vehicles they’re hit automatically, and that as one-weapon immobile ‘vehicles’ most of the damage chart will finish them off. It’s not a bad idea necessarily, but it’s also pretty risky; you’re probably not likely to get more than a turn of shooting out of them, two at the most.
One of the things that’s actually grown on me, the more I look at it, are the alternative turrets for the Hammerhead. Yes, for the most part the railgun is still the best choice, even with its high cost. But if you’re playing at lower levels, say 750-1250, all of a sudden the long-barrelled burst cannons (which should really be the standard Devilfish burst cannon) or the plasma cannons aren’t a bad idea. Yes, you’ve lost some of the flexibility of the dual-purpose railgun, but not much, and you’ve saved upwards of thirty points, which at those levels can really be worthwhile. Plus, you’ve probably got an XV88 or two already, and relatively limited heavy armour to engage at those levels.
The two Great Knarlocs, the Heavy Gun Drones and the various commander’s suits are all junk, though.
Heavy Gun Drones are just appallingly bad, a complete failure of imagination or design. Why they didn’t take this opportunity to do something interesting or useful with them I don’t know.
Great Knarlocs are still pretty poor, but with MC status they will at least kill something in CC before they die to Sweeping Advance. Of course, losing their cover saves due to being MCs means they are less likely to get there. I see they fixed the silly “majority Toughness” issue the Goaded Herd had.
The XV-84 Battlesuit is worth taking, if only for a 10pt BS4 (or 5) Markerlight. And the Markerlight does not take up a Hardpoint.
I am liking the Plasma Cannons, plus the kit looks pretty nice
True, the markerlight doesn’t take up a hardpoint, but it’s a heavy weapon, and how often is your commander so perfectly placed that you don’t want to move him for a clearer shot or need to move him for a cover save? Especially with Remote Sensor Towers and those lovely little 55-point, BS4 Tetras on the field generating their own cover saves against long-range shooting, I just don’t feel like that single markerlight would really balance out the limits the XV84 imposes.
I am, however, starting to ponder the utility of a commander in an XV81, with the AFP, a multi-tracker and a targeting array. You could really do some damage to horde armies with that one unit…
And yeah, the Heavy Gun Drones are just… I mean, I don’t even know what to think about these things. Does anyone honestly think that a slightly cheaper, slightly less capable XV15 is going to do any better in the Heavy Support section than the Elites section? I mean, I’d maybe consider it in smaller games, when I could just slap a couple of ’88s into one unit, give the squad leader a target lock and have a free space if they were the cost of a regular Gun Drone, but minimum fifty points just for two of them? Forge World, you insult my intelligence! I say good day to you!
But I’ll still take those Tetras, Forge World. I’m mad, but I’m not crazy!
Lol – I might just pick up another two Tetras, myself.
I see your problem with the XV84 and 81, now. The Tau Codex says that Crisis Suits cannot move and fire Heavy Weapons, correct? I believe the exact wording is they “must remain stationary to fire.” This is why Broadsides need ASS to move and shoot in the same Turn. But – Battle Suits are Jetpack Infantry. Which means that per the Main Rulebook they automatically have Relentless. And the wording of Relentless – this is very important – is that units with Relentless “count as being stationary” when firing Heavy Weapons “even if they moved in the previous Movement phase”. Put them both together and your Shas’os and Shas’els can move and shoot those SMS or Markerlights
If I was going to ‘fix’ Heavy Gun Drones, it might be good to merge them with Sniper Drone Teams, allowing the creation of larger units of drones that can move and shoot Rail Rifles, with an option for other weapons. Say 2-6 Drones, no Spotter, Jetpack rules, comes with Target Lock and TL Rail Rifle, and can upgrade to TL Plasma or TL Fusion Blaster, one per three Drones in the team. And then use the same 0-1 restriction as SDTs, and also allow up to three units of Heavy Sniper Drones in one FOC slot. Give them some Formation rule to encourage players to take more than just one squad (eg. if you have more than one unit of Heavy Sniper Drones, they are rolled for in reserves as one, and when they deepstrike the first one scatters as normal (subject to Marker Beacon) but any other units of Heavy Sniper Drones may be placed, without scatter, within 6″ of the first). Alternatively, if you start them on the table, then if one unit benefits from a ML token, all other units of Heavy Sniper Drones within 12″ gain the same benefit when shooting at the same enemy unit. That would not be a bad use of a Heavy Support slot.
Hah, nice try! Unfortunately, the codex is quite specific about it; “The battlesuits are designed to compensate for the recoil of light weapons fire, so they do not count as moving when they fire Rapid Fire weapons. This ability does not extend to heavy weapons, however, and the user must be stationary to fire them.” It’s a pretty clear line drawn between ‘counts-as’ and ‘actually is’, and of course, the special rules in a codex always overwrite any general rules from the BRB. So yeah, XV8s with heavy weapons just don’t seem like a very valuable combination to me, because XV8s are extremely vulnerable to increasingly common S8 fire, and the more exposed they are, the more likely they are to end up eating krak missiles and fire from psyfleman dreadnoughts.
Hence, the potential value of the ’81 with the AFP; you can fire completely obscured if you want, and if not, you can still sit mostly-covered and not give the enemy a cover save from your own protection.
Your Heavy Gun Drone rules are certainly a lot better than those Forge World put out!
It’s your army, so if you want to play it like that it’s fine by me
Plus it’s Forgeworld and we generally don’t get to play those models anyway. Still, if you’re not convinced that “counts as” stationary does not actually conflict with the Codex at all, and in fact is a really nicely worded rule that fits perfectly with what the codex says, have a read here – http://www.advancedtautactica.com/viewtopic.php?p=152762#p152762
True, it doesn’t really matter, since I don’t attach marker drones to my XV8s, the only way to get a heavy weapon in there. But I still don’t buy the argument that the ‘they don’t count as stationary’ rule specified in the codex doesn’t conflict with the ‘they always count as stationary’ in the BRB. And since codex special rules always override BRB general rules, I don’t see any way for XV8s to be able to move-and-fire heavy weapons.
So, I don’t know if you’re still following the discussion on ATT, Sholto, but just in case you aren’t? I think Nevar and I have just demonstrated that pulse carbines force pinning tests for any successful to-wound rolls, regardless of successful saving throws.
I haven’t been on ATT for a long time, but I will take a look. Colour me unconvinced, for now
It really annoys me when contradictions like this turn up in GW rules, especially when they don’t address it properly in an FAQ. Now I expect there are lots of Tau players wondering if their battlesuits can move and shoot heavy weapons (I think they should be able to, I mean terminators can and the suits are way bigger) with no clear answer from the guys that made the rules in the first place.
There is a similar contradiction in the eldar codex with the warp spiders. They are classed as jump infantry in the rulebook which allows them to deep strike, but their exarch can buy a power which allows the unit to deep strike. Luckily for me (as an eldar player with 14 warp spiders!) my gaming friends allowed me to deep strike my spiders without buying the power, but I imagine there are some rules lawyers out there will argue the toss and make their opponents buy the power.
Well, I doubt there are ‘lots’ of Tau players worrying about it, Dave, since aside from two special issue Forge World suits, you can’t actually get heavy weapons on an XV8 battlesuit. It may be a poorly worded set of rule interactions (or I may just be a particularly determined contrarian on this one), but it’s probably one of the most esoteric and hypothetical things two Tau players could find to argue over in their codex.
The Warp Spiders thing is just weird, though. I can’t imagine what GW were thinking with that Exarch power, since there’s not even a half-hearted, half-garbled rule slipped in there that indicates that Warp Spiders can’t naturally deep strike like all other jump infantry.
Thanks for the reply Garnet. I think it stems from the fact that the current eldar codex was written to work with 4th edition (and blimey does it show now!), and if I remember rightly back then deep strike was a mission rule and not a rule given to all jump infantry.
Therefore in some missions deep strike could be used and in others it couldn’t. Unless you were a space marine terminator that could always deep strike of course.
All it would have taken would have been from GW to include in the eldar faq that warp spiders could deep strike without buying the power. That would have let them replace the power with something else, say rending for the exarch and his squad