Gamestop posted this:

Who's excited for Doomsday in Injustice: Gods Among Us?! Join the Red Son Party (http://bit.ly/W8RjCl) to watch him in action in this exclusive new video and help unlock the game's opening cinematic!

Once you sign up, you get to see this video:
https://www.youtube.com/watch?feature=player_embedded&v;=9Bd7mmZPejY