Furthermore, production on MvC3 began before the success of Marvel vs. Capcom 2's release on Xbox Live Arcade and the PlayStation Network. When MvC2 came out, Capcom and Marvel were both smaller companies and the legal side of it was easier to deal with.
Despite the almost two-years of development, MvC3 is scheduled for a spring 2011 release. Around 30 characters are currently planned, though more will likely be added. Capcom is currently polling fans about their favorite fighting game characters.
Yay! That means the game now HAS to live up to the hype :)