I really hope they go nuts with the character roster!
Link from Minish Cap, WW and TP (with wolf transformation!)
Zelda from TP and WW
Mario from SMS (and M128?)
Luigi from LHM (and M128?)
Capt. Olimar from Pikmin2 (sidekick can be color swap chatacrer)
Samus from Metroid Fusion or PE (with dark or light suit and weapons!)
Maybe some Animal Crossing characters?
You know, Link in the past has just been an amalgum of every Link in the SSB games. That's likely going to be the case here too.
A lot of that seems like a costume change or a special item.
Captain Olimar... I can see that! Game starts, your opponent just stands there looking confused, then they start getting an arse handing to by a pixel tall horrific alien! ALL his moves would be giving orders to pikmin. By that I mean he'd have the Olimar quick punch, but everything else would be like a wave of pikmin forming various shapes just appearing from the ground and doing things AT you.
They need to add Wario, Pit, and Little Mac though!
And as a joke character, Tingle!
I've always said I think Tom Nook would be a great SSB character. He could chuck furniture, axes, and crap at you. He could use a net to temporarily stun a fighter, or use a fishing pole to pull an enemy closer ala MKs Scorpion.
I want Ganondorf to return since he's my best in Melee (although everyone from SSB was in Melee, so I have little reason to doubt every characters return), but perhaps with a transformation into Ganon. They successfully did the transformation thing with Zelda and Sheik, they could do it with the 'Dorf!
New items could be FLUDD (kind of like a fire flower with longer range), Pikmin (different colors can do different things!), the flying blue spiky shell from Mario Kart (automatically hunts down and attacks the fighter currently winning the fight!), and the Poltergust 3000 (maybe suck enemies in and spit them out off the edge of the stage).
Finally, the other characters I want in the next SSB are Paper Mario, Olimar, Wario, Waluigi (you know he'll be there), and FOR GOD'S SAKE, Geno from SMRPG!!
The Mine Thrower from RE4 :D
Here's an obvious one: Dark Samus
And how about Liqued Mario complete with paint brush? :D