Man, it'd be awesome if they did a brand new Street Fighter in all HD and shiz.
Oh wait. :'(
In all seriousness, Capcom owned the beat-em-up genre, and I'd love to see them get back to the more pure examples they used to turn out so regularily (not that Viewtiful Joe and DMC aren't great, just that I liked the meat-and-potatoes stuff). If they got to remake The Punisher arcade game they did, that would be awfully sweet. Same goes for Final Fight 3 (underrated).
And if I were allowed to be selfish, I'd like another 2D shooter out of Capcom, not a dual-joystick shooter, I'm talking Vulgus:2008, or something, yeah, that'd be nice.