Tracy Erickson from GamePro writes:
"Hot on the heels of his resurgence in popularity thanks to the success of The Dark Knight, the Joker will be making an appearance in Midway's much-anticipated brawler. Creative Director Ed Boon revealed during Comic Con that the Joker, Green Lantern, and Captain Marvel are joining the Mortal Kombat vs. DC Universe cast, although none were available in the limited demo I played. Instead, I brawled with a smaller slate of characters including series mainstays Scorpion, Sub-Zero, Sonya, and Shang Tsung. Batman, Catwoman, Flash, and Superman represented the DC side. The character selection screen still has at least 10 empty slots, so I'm certain Midway will tease the wait with regular character reveals in the ramp up to the game's release."