Blizzard released a list of the top team of each battlegroup for the 5vs5 arenas. Click for their armory links.

Bloodlust“Power Trip” from Tichondrius
Cataclysm“Fuddruckers” from Auchindoun
Cyclone“Outplayed” from Daggerspine
Emberstorm“Front Line Assembly” from Tortheldrin
Frenzy“ATM” from Area 52
Nightfall“C A P S L O C K C R E W” from Kel’Thuzad
Rampage“Dejthstoneibilyfunecima” from Cho’gall
Reckoning“Portable Hotdog Steamers” from Smolderthorn
Ruin“Rerolled” from Azgalor
Shadowburn“The Challenge” from Dark Iron
Stormstrike“Yea We Lift” from Mal’Ganis
Vengeance“The Fighting Mongooses” from Mug’thol
Vindication“Clan HeX” from Lightning’s Blade
Whirlwind“Game blouses” from Cenarius