In WWE All Stars for the PS3 and Xbox 360, there is a cheat you can enter to unlock all arenas, wrestlers, and outfits in the game.
PS3: At the main menu, press Left, Triangle, Down, Left, Triangle, Square, Left, Square, Triangle, Down, Right, Square, Left, Up, Square, Right
Xbox 360: At the main menu, press Left, Y, Down, Left, Y, X, Left, X, Y, Down, Right, X, Left, Up, X, Right