That's right ladies and gentlemen, the one and only Dread Dormammu has been confirmed for Marvel vs Capcom 3!
For those of you unfamiliar with the character, Dormammu is the ruler of the "Dark Dimension", an alternate dimension not far removed from ours, which as the name implies is not a very happy place. The longtime arch-nemesis of Doctor Stephen Strange, Dormammu will be recognizable to more recent comic fans as the source of Parker Robbins' powers, whom you might know better as The Hood.
Based on the above (incredibly awesome) trailer, it appear as though Dormammu will be appearing in a boss capacity, most likely as the final boss of the game. This role was filled in previous games in the series by Marvel characters Thanos, Apocalypse, and Onslaught, as well as original character Abyss.
Dormammu will be joined by Marvel Comics characters Captain America, Deadpool, Iron Man, The Hulk, and Wolverine, along with Chris Redfield, Dante, Felicia, Morrigan Aensland, and Ryu representing Capcom.
Capcom has announced that at least twenty more fighters will be added to the game by the time it releases sometime in 2011, for the Playstation 3 and Xbox 360.