I haven't followed it because GameCube is my only console but the Game Informer article had some interesting things in it.
Ok I got a Game Informer for May yesterday and today I look at the pictures for the MK: D preview and whatnot and I see a guy I haven't seen before. He's got white hair and wearing a black armor-ish suit.

At first I thought he looked like a young Raiden but I'm not sure who he is.

On page 55 at the top he is fighting Ermac and and on another series of pics on the same page he is fighting Mileena.