Since we are still 2 weeks away from true PvP, I have been gearing up through all of the heroic 5 man dungeons that Wrath of the Lich King has to offer me.
I am enjoying my best PvE damage with this spec (I believe this to be a very popular spec):
Volley is still the bread and butter of PvE and Serpent's Swiftness and Mortal Shots help make it very strong. And on boss fights BM is great. So there is really no downside except for the constant spam of Steady Shot making it the most bland raiding spec (luckily Volley is still fun for me).
I believe pretty much everyone will be sporting heavy PvE gear throughout half of the 5th season of arena. Burst damage will be key, and Paladins will be strong in Arena's because of their negation of burst (Divine Shield and Hand of Protection).
I'm going to be playing mainly in 2's with a Rogue and in 3's with a Rogue and a Death Knight. Hopefully we will have some success somewhere. I really hope Hunter's get a few more survival buffs and a few more on the run damage buffs before too long into arena season 5.