Following up on Azuro's post, but for Horde members.
Not too worried about CR at the moment, but prior experience is definitely worth noting.
In MOP, I took Mistweaver/Warrior/Rogue to 2.2k in 2's, 3's, and 5's. In Warlords i'm mainly playing Hunter, Warlock, DK, Rogue, and Priest. All are above 1.8k CR without really trying and using less skilled players in the arena finder. I got my mistweaver account banned, so I lost the arena achievements, but can prove to anyone that it was me doing it.
Requirements:
You'll need the paid version for TuanHA or Gladiator Suite
For 3's - I have almost every character, so alot of the top comps are completely open (Any combination of Ret Paly, Combat Rogue, Frost DK, Hunter, or Affliction Lock seems to be the meta at the moment)
Also looking at putting together a potential RBG team (Horde)
Would be a little more difficult to do, but let's see if we can put together some successful arena teams first.
If you are interested post on the forum here with skype/btag