Joining the cast is none other than Martian Manhunter. I don't really know much about him, other than what I can read on Wikipedia, but his powers look similar to Superman's.
Green Lantern fans should also pay attention to the trailer above, as it looks like a skin of the John Stewart version of the mystic hero is making it into the game.
So Injustice fans, is this the character you were hoping for? If not, who would you have like to have seen join the ensemble?