NEW ROSTER UPDATE: VERSION 4.7!!!! ( Okay I added Sonic back, no more updates for now.)
Noticeable differences:
Matthew - Most people have Issac, as he appears in all the titles. I have Matthew because it seems he has replaced Issac's role and is mostly a reboot of him. This will be a more relevant way of representing Golden Sun. But both are very likely, but I go with Matthew.
Starfy - Starfy is one of the most likely, he's had 3 GBA installments, a 4th on DS, and a fifth western release on DS. He has become a pretty big Nintendo All-Star and has a lot of Move Set Potential. I suggest others add him.
Sheriff - He was the first Nintendo game (not counting
Computer Othello.) as well as an international arcade title, he can represent the arcade and his status of recognition is similar to that of Ice Climbers.
Mewtwo - Everybody knows Mewtwo is coming back. It's inevitable. Since his new awakening form is a limited power up, I made that the Final Smash.
NEW! Genesect - My newest addition. I didn't add Genesect because he's a new Pokemon, I added him because we need a Pokemon that hasn't already been playable. Genesect fits the description Sakurai gave on how he adds Pokemon characters. Genesect being in SSB seems very likely and has so much potential.
Paper Mario - Bowser Jr is very likely to be the 5th Mario rep, but I see Paper Mario to be more preferred and unique. It just seems like the more logical choice.
Bomberman - Konami has recently acquired one of the most popular/iconic third-party characters from the deceased Hudson Soft. Bomberman has had as much affiliation with Nintendo as any of the third-parties if not more and has had games on practically every game machine since NES. It hasn't been confirmed that third-party characters will return and Sakurai and Konami may want to make use of this character.
Snake - Most games that have guest characters usually only have them once. If any game does that it should be Smash Bros. I'm sure Sakurai may want to prioritize Nintendo Characters in a Nintendo fighting game, and not have too many Third-Parties. We could have Sonic, Snake, and Mega Man, and though it's hard to imagine SSB without Sonic, there is the possibility either 3 will be too many and Sakurai may want a second third-party to have a chance. I just don't see third-parties as veterans, but Sonic seems too popular to leave.
(I know Snake was added as a favor, but it was a request for him to make an appearance, not be a veteran for life. That'd be a pretty huge favor)
Mii - I think it's obvious he will use moves from Wii Sports, Wii Party, StreetPass Quest, and maybe even Pilot Wings Resort.
Costumes:
Villagette - I predict half of Villagers colors will be Boy, and the other half will be girl.
Dry Bowser - Either 1 costume or a second set like Wario & Villager.
If you have opinions or constructive Criticism, please give suggestions below.
(Credit to Ariand/AEM for making the Backgrounds of Palutena & Sheriff)