Actually, while we're on the topic of SSB ideas, they should make a game that combines all of the smash games together into one. Every character from every game, meaning fox from all 3 versions, kirby from all 3 versions, as well as all the stages and items.
That'd be sweet. It'd be cool, it would allow those who liked playing SSB or SSBM to play against people who like brawl more without having to adapt.