Sony has announced that Playstation All-Stars Battle Royale will be available in North America October 23rd. Along with this announcement they have revealed some of the bonuses that you get for pre-ordering either the PS3 or Vita version (supports cross platform play).
It should be noted that the game will have a much larger character roster. The two mystery characters will be announced later today at Evo 2012. These alternate costumes work on both systems of the game, so no need to pre-order both if your worried about the costumes.