Firstly -- a new, surprising game would be very welcome.
But as there are bound to be sequels announced given the nature of the story (the properties that Capcom has in it's "vault"):
Hopefully Street Fighter IV *is* coming. And hopefully it would be scalable to all systems. It's something that'd look sweet in HD so I suspect 360/PS3 versions would be inevitable, but it'd be damn fine to have on Wii as well. In fact, I prefer the classic controller's D-pad to the other consoles' really. SFII on XBLA has convinced me of the need for online.
If a Megaman game is announced, I hope they do something neat with it so it doesn't seem like a spin off or the 9 millionth iteration in a series that people are finding hard to follow.
Viewtiful Joe 3 would be pretty sweet. I can imagine VFX possibilities using the Wii remote would be really good.
If there's another Okami, I want them to get rid of the annoying Jibber talk. It's the only complaint I have.
I don't want Resident Evil 5 on Wii per se, but I want another game that uses the pointer like RE4. I can't imagine playing RE games any other way now.
I'll take a new Powerstone on anything really. Online plz.