Rodaku... Geno will only have a chance in if Square Enix allows it... Geno made a random cameo in one of the Mario and Luigi RPG games and they had to get rights from Square.... just for that one cameo... and SE are whores when it comes to licensing
Capcom will be more then willing to do donate characters... even for free...
Sonic is to popular to get rid of, Lucario may not reappear, but Zoruark is not popular enough to be in the game i don't think, The guy who made snake practicly got on his knees to get Snake in Smash, they were considering putting snake and Lucas into Melee actually but it was too late in development to add them...
Lastly, Like i said 3rd party has me incredibly interested, at E3 the game companies that said that they are interested in working in future nintendo titles are:
Capcom, EA, Activition, Namco, Ubisoft, and Konami...
so... this is my guesses for who may or may not make it in...
Capcom: Ryu, Chun-Li, Morrigan, Megaman, Zero, Tron Bonne, Chris Redfield, Albert Wesker, Amateratsu, and Dante
(Potential Pheonix Wright themed stages?)
Namco: Siegfred, Jin, Heiachi, Agumon, KOS-MOS, Lloyd, and Pac-man
Konami: Snake, Alucard, and Simon Belmont
(potential Dance Dance Revolution themed assist Trophies and Stage?)
Ubisoft: Rayman, Rabbid, Ezio Alditore, Prince, Travis Touchdown
EA: (potential Spore themed stage and assist trophies?)
Sega: Sonic, Tails, and Knuckles
(potential Phantasy Star, Super Monkey ball, and NIGHTS themed items and stages?)
Activition: (Potential Call of Duty and Guitar Hero Themed assist Trophies and stages?)