My main role is that of tank, specifically protection warrior. I levelled up as one, took a secondary spec as Arms as that was the least loved PvE spec there was in warrior specs and stuck with it.
4.0.1 brought many changes with it. Most meaningful for me was the fact that the button mashing and responsiveness of the action buttons was replaced with skill queues and much slower paced, cooldown based gamestyle. I'm still fighting to be patient enough to wait for the skills to be ready, and usually end up banging the same skill twice due to queuing.
The whole issue I have with the current, slowed down action system is that of learning the new pace of play. In addition to this the AoE threat generation of protection warriors was lowered to almost non-existing, meaning that in multi-mob pull the over effective ranged DPS will steal one or more mobs from the tank even in the best case scenario. The only guidance I can give is to let them have it, as in 5 man heroics the DPS will kill any normal mob fast enough to survive the onslaught. The tanks responsibility in multi-mob pulls is to protect the healer nowadays, instead of protecting the whole group as it was before the 4.0.1.
With single target threat there is no such thing as aggro problem. Really. Shield Slam and Revenge take care of the needed aggro and if you take care and push that Heroic Strike there as your rage dump, you will fly high above even the most aggressive ranged DPS there is.
Mainly because of that sluggish feel to the protection play I have recently been playing as Arms dps. Granted, my DPS gear is lousy, mainly quest blues and a couple of lv200 purples to shine it with, but still there is some nice DPS to give in the encounters. Seldom I sit at the bottom of the DPS meter after a heroic, just above the healer (that happens, too, but then the rest of the group is in tier10+ and even the tank delivers outrageous 5k+ damage). On the average the DPS goes in the range of 3.3-3.5k depending on the heroic: the more there are multi-mob pulls, the lower it goes as there are not too many area DPS options open for us. On the other hand, in single target boss fights I can easily go above 4k as the Execute still brings in nice crits when the mob is below 25% of it's health.
And as Arms I very seldom see the sluggish feel take away the fun from the play.
Arms as a tree is a peculiar one. You have distinct separation of PvE and PvP talents in the tree, some of which are not at all useful in the other role. I can see several of the talents I passed work extremely effectively in PvP, but have no use in PvE encounters. Then again, either way, the build is very, very easy to come up with, even without any EJ originating number crunching.
Strenght is still the main stat to go for, as long as you take care of the cap values in Hit, Crit and Haste, in that order. For hit the cap is 263, still, and anything above that is a waste (Correction: The current hit cap for melee is 8% which equals 246 hit rating. That 263 was the base before 4.0.1., adjusted by talents.). I think the cap for Crit is around 70%, so as much as you can muster is best and the same with haste. As long as you keep strength a the primary focus on gemming, you should be doing great, really.
At least that's been my philosophy, and so far it has served me well.
All in all, even though I've seen Fury warrior in 5 man heroic delivering above 11k DPS, I can say that Arms is a valid, but not as shining DPS spec. Like before, Arms will not rule the DPS meters, but will deliver without a fail.
The overall impression of these warrior specs for me is that the slower pace requires a lot of practise and slowing down properly requires that your computer can handle the game at reasonable frame rate during the combat. The queuing will ruin your day if you lag, but as a plate wearer, the result shouldn't be catastrophic unless the boss hits unexpectedly hard.
Warriors are definitely the crop of the earth: not necessarily the best of all classes for their selected roles, but best in what they do, and most definitely the steadiest and sturdiest of them all. We are the cannonfodder and the ones who stand last: not something any other class can say.