Warriors are great tanks and under appreciated DPS.
To current warriors or those thinking about becoming a warrior. Don't let anyone tell you that you can't DPS. It's often other DPS classes telling you this, why? Because they're scared you'll put them out of work.
First and foremost, the easiest way for a Warrior to DPS is a Dual Wielding, Fury build. http://www.worldofwarcraft.com/info/classes/warrior/talents.html?tal=150050013020000000000000505300250521205210510000000000000000000000
17/44 is the prime PvE spec. You don't have to go exactly as I have it, Improved Slam is a must though. I chose Improved Cleave simply because I can hit two Mobs for 2k+ each. Who else could do that but a warrior?
You'll have an easier time getting your self Raid ready with this spec. You can skimp by and still DPS like a crazy person.
Raid Minimums for 17/44 DW Fury- 10k HP unbuffed
30 crit
1600-1900 AP unbuffed
130 hit or more if you aren't going to sacrifice AP.
Taking this spec into an Arena/BG situation CAN work. But you'll have a really hard time getting yourself tough enough. Enchants, Gems, etc; you'll need the best of the best to DW in a PvP setting.
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Which leads to the two handed DPS warrior. Sorry Retribution Paladins, you can't match us. Sure, you're pretty tough. But you just aren't tough enough.
You can take the below spec into a Raid or the Arena, it will be much easier to Arena in this spec. Two hand weapons hit like trucks against other players.
http://www.worldofwarcraft.com/info/classes/warrior/talents.html?tal=050050213525100200210000505000500521202000000000000000000000000000
You can Raid with this spec. But the gear hunt is much harder. You'll need Executioner or Mongoose, no ifs, ands or buts. Be prepared to fork over cash for Epic gems. You will need Improved Slam again here, it brings your weapon down in 0.5 seconds no matter what the speed. With the right gear, even a DW warrior won't be able to match the unstoppable carnage wrought by the 2h Wield warrior. To do so will be much harder, but worth it.
Minimum Raid Stats- 10k HP unbuffed
100-120 hit, no more. You'll REALLY need the AP here.
1900+ AP unbuffed
30 or more crit
For both Dual Wielding and 2h, if you can travel with an Enhance shaman dropping a Wind Fury totem, you'll be the top DPS'r almost every time.
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One final portion to DPS warriors. You will NEED a swing rotation.
I'll give you a good basis, after every WHITE NUMBER hit use Improved Slam. It ticks for a lot more that way.
Coming Soon, 'How To Prot Warrior Like You've Got A Pair'