In response to the Grand Theft Auto comment...
Grand Theft Auto Advance is a Gameboy Advanced game, so A GTA game has appeared on a Nintendo system. R* is also backing up the Wii with Manhunt 2, so I wouldn't say that Nintendo pushed developers away by targetting a family audience.
As much as I'd like to see Mike, the protagonist or antagonist (depending how you look at it) of GTA:Advance in SSBB, I just don't think it's feasible. Not because Nintendo pushed away developers, but because of the overall amount of violence and controversy involved in the GTA series. MGS is rated M, and Snake still made the cut, but I believe that's because his moveset doesn't use any realistic guns, only explosives. It'd be hard to make a GTA character be able to fight without using guns while avoiding the controversy of their inclusion in the game.