This build (the level 70 version) skips on some pretty attractive talents in fury in order to start picking up talents that improve offtanking/five man tanking viability at level 70. Tactical Mastery means that Bloodthirst generates more threat when used in Defensive Stance, while Deflection is just a bread and butter tanking ability, five points to get five percent parry. Over in Prot, we see 2 points in Imp TC to improve our AoE tanking as best we can, while we still went 51 points in fury for Titan's Grip and Bloodsurge for use outside of instances. Piercing Howl and Heroic Fury are very nice for tanking, slowing mobs you don't want peeling away and allowing you to clear any roots or snares that keep you from gathering mobs up.
What does this build lack? No enrage, although I often skip that talent anyway: it's good for soloing, admittedly, and in a tanking situation you're getting hit as well but it's still five points that you need to trim somewhere to hit Titan's Grip. No Intensify Rage, no Rampage (I personally love Rampage and would love to have it, but if you're going to run with a feral druid you might as well skip it... if you absolutely cannot imagine not having it, drop a point from Improved Berserker Stance for it) and no Unending Fury. None of these are strictly speaking necessary for a fury leveling build that's shooting for some tanking viability, of course. That doesn't mean they aren't good talents, but you can't have everything in a spec that's shooting for relatively deep investment in both Arms and Prot.
The level 75 version of the tree continues up into protection. The two points in Shield Specialization improve survivability while tanking but they're really just there to get you fully into Incite, which in addition to providing some solid AoE threat from Cleave and TC also means that Heroic Strike gains an extra 10% crit chance. For soloing/grinding/instance DPSing this is a fairly solid talent if you're going to have the points in protection (since you won't be able to reach Impale with this much in the tanking tree) for both single target and multi mob DPS situations. Peronally, I wish Incite and Imp Bloodrage would switch positions so I could pick up full Incite without going so deep into protection, but if they did that, I suspect almost all Arms and Fury warriors would pick it up.
At level 80 (changed to show you how easily one could pick up Rampage if you just don't have a feral druid handy) the spec finishes up with Incite and then goes up arms in order to pick up Impale. Heroic Strike spam will be a big part of this particular fury tanking spec, meaning that a relatively fast 2h weapon as your main hand may in fact serve you well if you choose to tank with one.(I'm currently playing with my Titansteel Destroyer when I try this.) There's certainly no reason you can't use a normal tanking weapon with this spec, however, I'm just stubborn and so far tanking with a 3.4 speed 2h with lots of hit seems to be working pretty well: while rage generation isn't quite as smooth and I do need to use bloodrage more liberally than otherwise, on the whole you can very solidly tank level 80 five mans, even heroics, with this build as long as you are in high hit tanking gear to help minimize the chances of a missed Bloodthirst.
I'm in no way attempting to proclaim this build as superior to prot for tanking or the most efficient DPS build possible: it's neither of those. What it is aimed at (and what I've found it more than capable of doing) is allowing me to go out and grind dailies while dual wielding two big 2h weapons without completely losing the ability to tank when asked to. Not everyone wants to tank, however, and some of us go fury because we have absolutely no desire to deal with tanking whatsoever. That's fair. What spec for them?
One possible build for fury warriors who are looking towards a path to five man and raid DPS is this spec. It assumes a lack of feral druids either due to soloing or there simply not being one in the five mans you run: if you're going to be fairly secure in the presence of a feral you can drop Rampage for Heroic Fury or an extra point in Unending Fury. This build leaves out Bloodsurge because, while I am personally very fond of this talent and love hearing it proc, it's still a proc based on a crit off of a relatively small amount of your attacks and gets in the way of your climb down the arms tree for Impale.
At level 75, however, you can have full Impale and full Deep Wounds for a TG spec. Not only does this get you the very nice damage of Deep Wounds ticking away, it also gets you closer to the whole reason you're climbing this deep up arms. Level 80 shows us the whole story, as you now have Impale, Deep Wounds and full Two-Hand Weapon Specialization along with maxed Unending Fury for a purely damage oriented build. The build costs you some nice talents... Heroic Fury, Furious Attacks, Intensify Rage and Bloodsurge... but if you're looking to break out the hurt on dungeon mobs it's a very solid design.
Things to keep in mind: if my math isn't wildly incorrect (and it often is) you need roughly 360 hit rating with full Precision to ensure that you don't miss special attacks like Bloodthirst, Whirlwind and so on while dual wiedling 2h weapons with Titan's Grip. This is certainly not impossible, but it does require you to prioritize hit at least until you're in epic gear. My 2h weapons always have Titanium Weapon Chains on them, hit enchants to gloves and Icewalker on boots can help bridge the gap, and I gem for hit whenever possible. It's quite doable to hit the 360 hit rating you would need to not miss with specials. The 820 hit rating you'd need to not miss at all while dual weilding... no, I wouldn't even attempt it. You would be horribly gimped for DPS.
That should do it for leveling specs: I of course expect you guys to come up with ideas I didn't, as there's always more to consider and more to learn. Next week, we'll talk about gearing up to tank/DPS in Naxxramas, since I just started raiding there myself.