I'd love to see some form of mutiplayer/tournaments implemented. The current iteration seems like a very solitary experience.
Oh yea, I dont think we'll see 2 player head to head any time soon, the Roms werent made to play that way in the original tables. And 2 player online hotseat doesnt sound too interesting to me.
Sounds good to me especially if it was with a friend and you had some sort of voice/video chat system. Don't mind watching someone else play.