Dawnstar had the Avengers.
Falkreath had the Dark Shadows.
Markarth Side had the Frost Demons.
Rifton had the Furies.
Haafingar had the Ravagers.
Whiterun had the Devastaters.
Windhelm had the Paladins.
Winterhold had the Annihilators.
I personally don't there will be an arena-esque guild in the game or even a place to where you can go fight for money. However since Oblivion had the Arena, Fallout 3 had The Hole, and Fallout: NV had The Thorn and the Legion Arena it raises my hopes. Perhaps even as DLC? What do you think?