The problem I see for Geno is unfortunately Square themselves. We know from Cloud that their approach to Smash is business-first, no-fun-allowed: if they're going to be in this, I'd wager they're only in it to make money--and not just from shares in DLC revenue, but also though advertising. I'm sure they know Geno is a popular pick among Smash fans, hence them licensing him for the Mii costume (and apparently the Spirit/player icon?), but I'm not convinced that, given the option of giving Nintendo another character, they'd see him as a big enough draw for the general audience. Certainly they could let Nintendo use him in future Mario games (Who am I kidding?), but besides Virtual Console and the SNES Classic, they wouldn't get much for advertising out of him either.
Just my thoughts, anyway. It could be in 2-3 months that we get Geno Shoots for the Stars and I look like an idiot. Never stop dreaming until the end.