Looks like Guitar Atomik was right. In this new trailer for Marvel Vs. Capcom 3, the dreaded Dormammu shows his fiery face in what could be a last boss/major villain-sort of role. No sign of Dr. Strange so far, but if Capcom's Seth Killian gets his way, I'm sure it's just a matter of time before the ex-Sorcerer Supreme makes his way into the proceeding.
Oh, and I got to play the game yesterday. It felt a lot like MvC2. Returning characters had all their old moves, though Felicia seemed to be beefed up a bit. She felt almost as combp-friendly as Wolverine. As for new characters, you probably already heard that Deadpool has the shoryuken from that one infamous comic panel, but did you see Dante's electric guitar move? He suddenly whips out a skull-y six string and begins to rock mid-fight. The game may have a more stark and serious art direction than previous Capcom Vs. titles, but it's still got the series self-acknowledging insanity.
I hope to get some more time in with the game today. I'll let you know what I find out.