Revealed at the New York Comic-Con, Capcom's confirmed that Ghosts 'n' Goblins' Sir Arthur will make an appearance, as will Bionic Commando's protagonist Nathan "Rad" Spencer. Interestingly they've gone with the rebooted Bionic Commando design, rather than the traditional character.
On the Marvel side, Magneto from the X-Men's been confirmed, as has M.O.D.O.K. We'd never heard of M.O.D.O.K either, but that seems par for the course with the Marvel roster.
We've embedded a gameplay trailers of the new Capcom characters after the jump. We can't wait to get annihilated playing this game.