Hot on the heels of the game's release and the subsequent DLC voting that occurred, Ryota Niitsuma was interviewed by 4Gamer (via andriasang) discussed Marvel vs Capcom 3, additional DLC, and further sequels. On the sequel front, among his wish list picks he indicated an interest in adding yet another Mega Man character. No word on who it would be, but it's safe to say that the fans have a good idea on who it should be. However, when it comes to DLC for MVC3 he said that while there are no plans for adding additional characters outside of Jill Valentine and Shuma-Gorath, adding characters would not be difficult.
Here's hoping they can iron out any potential kinks and make additional, unplanned DLC a possibility. Or we could always hope for Super Marvel vs Capcom 3!