Kinda disappointed TBH. A bit heavy on the FE characters. Wario, Paper Mario, or other Pokemon would have been preferred. Or Zero (from MM)? Or Leon Kennedy? Or Wolf?
You gotta understand: Fire Emblem: Awakening is apparently considered the best Fire Emblem game in years (possibly of all time), one of the 3DS's best games, and single-handedly raised the popularity of the Fire Emblem series in the west. Plus, Sakurai is a huge Fire Emblem fan.
Wario will be announced later. Paper Mario seems like a gimmick; I think Toon Link is pushing it as is. Zero? He's already in Mahvel. Leon would be a terrible choice for Smash. Wolf is a veteran I expect to be a secret unlockable, since he's very unique compared to Fox and Falco (and three Star Fox reps is a good number).
Big or not, that's still a lot of FE and a lot of similar fighters. Link, Marth, Ike, Robin, Lucina, plus the Mii duelist variant, then there's the possibility of Xenoblade characters being added. That class is starting to feel overloaded.