Well, what can be said about the new Tau? Well one thing is for sure, my love of the Tau remainds unchanged, i.e. I still hate the little buggers.
I'll not bother going through a full review, as I don't really care for the units and there are some nice round ups out there already and they will do a lot better job then I ever will. So what can I say? The new formation, the Hunter Contingent, is stupidly powerful, as would be expected, with some amazing special rules, namely the ability to combine their fire and also the bonus' of markerlights. the sub formation, the Hunter Cadre, is also pretty good, although it sufferes from the same issues as the other formation,in that it forces you to take certain units, although with the choices that Tau have means that they don't suffer much. The formation itself is pretty easy to see which way people will go, with Kroot and Vespids being left on the side line again, and 3 min units of Strike or Breacher. With the new rules for some units making them even more OP, Riptide for example can be taken in teams/squadrons of 1-3, and you can take 1-3 units, so possibly 9 Riptides, the story is the same with Broadsides as well. There are also a load of +1BS bonus' being handed around in addition to marker lights.
So, lots of super powerful monstrous creatures with lots of powerful weapons, twinned with markerlights to boost BS and remover cover, plus being able to combine fire power and ML bonus' means that they are going to be annihilate anything they shoot at.
And all this before we get in to the Auxiliary units! Which include deep striking and relentless Broadsides and Riptides (Retaliation Cadre) and hitting vehicles on rear armour (Stealth Cadre), bye bye Leman Russes,
And then how can we forget the new units! The Coldstar suit, Ghostkeels and Stormsurge. The Ghostkeel will just be a pain in the arse to deal with, but I'm not to worried as I have the ability to ignore cover, which is its biggest strength and the Coldstar suit will also be a pain, but again I should be able to deal with that with ignores cover and hopefully making it kill itself on a grounding test. The Stormsurge however, is a different story, especially if it plants its feet. With all that firepower it will quite easily destroy a large part of my army in no time at all. I mean 2x 4D6 missiles at S5 AP5, so on average that will be 28 shots (working on an average role of 7 on 2D6), that pretty much everything apart from a LRBT being destroyed, twice a turn, before you get to the main weapon! So yeah, its going to be a pain. It really will be a case of trying to destroy it before it gets itself planted, which I think will be nigh on impossible with my guard and hard even with my SM forces.
And with the very few nerfs that seem to be going around, Tau just got super powerful and are well up there with the Eldar and leave the rest of us floundering in their wake, ok, so SM 'dex isn't bad, especially with a full company, but the guard are going to struggle these days.
Well, there were rumours that guard were going to get an upgrade sometime soon, but I haven't heard anything else on that recently, so well see. Personally I hope that some of the other codex's get some love, mostly Chaos and Ork, as I think their the weaker ones at the moment. Some would say DE but personally I think there last codex was rather good.
If you want a proper codex review, I would suggest looking at the Elite 40k blog - http://elite40k.blogspot.co.uk/ although there aren't many full reviews up yet.