At first, I was an avid "Gamecube controller only" for SSBB, but realistically, I think Wii controls would work fine...motion control wouldn't really need to be used even.
You have your joystick in your left hand. Done.
You have your A and B buttons in your right hand. Done.
I mean, that pretty much takes care of the majority of controls right there. Use the C button for people who use a button to jump, and the Z button for shield...Down on the D-pad for grabbing...that pretty much takes care of all the controls...and I don't think too many SSB gamers would be upset with this configuration.
Along with that, they could add the options of using GC or classic controllers if they wanted.
LEFT4DEAD411.COM
Bet with disolitude: Left4Dead will have a higher Metacritic rating than Project Origin, 3 months after the second game's release. (hasn't been 3 months but it looks like I won :-p )