This seems to be more like
X-men vs Marvel Super Heroes than anything.
Yes, the marvel characters tend to be less precise than the Streetfighter characters, which lends itself to the limitations of the online play - but with characters as overwhelminingly
spazzy such as Wolverine you could be kissing goodbye to the last breath of strategy that the game had.
I would have thought that Ken+ Akuma would be some of the first ones you'd work on, as they share graphics and patterns with Ryu, and characters such as charlie or chun-li would add a LOT to the play style (some charge moves, some aerial supremecy, etc).
I think this is a great project - brilliantly ahead of any other online web-game, but I don't think opening up the character roster to votes is the way to do it. Not unless you want to make Cheap-men vs Mashfighter....
Game Balance, alas thou hast forsaken thee!
--dock