Uh. Fine, look, go with DK, it's just much easier to use.
On warrior the stance restrictions and the rage system will cause too much limitations, specially if you're new to the class. And when Wotlk was released was like santa gave anti-warrior kiting spells to every class for christmass. So warrior ends up being pretty much just an anti-heal support element in a group, not an actual stand-alone PvP character. And don't get me wrong, warrior is a very much very fun class to play, in addition things change from patch to patch and blizz are clueless about how to fix the class so it's just a matter of time for warriors to become OP as result of future changes, but as of now they're still possibly the worst for PvP, specially for a beginner.
On DK nothing is stance restricted. You never get rage starved and don't lose much for switching presences. Mostly because you don't even need to switch presences much because none of your spells are stance restricted. With the exception of Anti-heal debuffs, everything a warrior can do the DK can do easier and better. The other advantage warriors have is that their debuffs cannot be dispelled.
Depending on spec and glyphs DKs can do things like AoE damage that snares or crazy things like that.
And Death Grip is insane. In BGs and such charging into a group makes you dead, instead using death grip on someone makes that someone dead, you don't even need to do any damage, just by making some enemy land in the middle of 3 teammates he gets killed in less than 5 sec without giving him any chance to fight back or do anything. In battlegrounds this is an instant "you die" button on every cooldown. And it has a huge distance, you can separate someone from his healer or a healer from his group by using death grip and making them land faaaaaaaar from their teammates. Or you can use this to force someone to land near NPCs so that the NPCs aggro and help you.
As a bonus you get to skip about 60 levels worth of grinding. And starting a new char on a new server with DK isn't like starting a warrior and having to suck the first few quests because you don't even have enough bag space to loot the quest items.
So yes, it's pretty obvious that dk is still the better choice of the two right now.
PS: Anyone that disagrees or thinks that I am somehow misinforming the OP is welcome to share his views and correct on any incorrect information I may have posted...
Edited, Apr 25th 2009 8:23pm by xorq