Time to play around with some more speculation...If the 35 character roster on GAF turns out to be de facto (leaving 12 characters to know, none being 3rd party supposedly), here's what I believe is likely...
Mr. Game & Watch - Following the franchise icons on the Dojo, a single icon is missing right in the middle of the other known Melee ones...Not too hard to figure out...
Luigi - Another no-brainer...There's no need to argue his existence...
Ganondorf - Aonuma talked about how his team sent in Sheik and Ganondorf models, and with the emphasis on villains I don't see him being pulled...
Captain Falcon - Red Alloy...Plus I don't see them yanking a franchise altogether...
Jigglypuff - The guy who does Snake's voice-acting mentioned her in an interview...Iffy evidence, but enough...
Ness - Lucas stealing his moves puts his spot in jeopardy...However, it could be that they will replace his attacks with an all-new move set
Marth - The icon of the Fire Emblem series...With his remake incoming, his place could have been fortified...
Mewtwo - While an icon in prior Pokemon games, his place may have been usurped by a new Pokemon...We shall see...
That is
8 likely vets, leaving at least
4 newcomers...The most likely candidates:
Wind Waker Link - With his popularity and increased presence due to being in Phantom Hourglass, he makes a strong choice as a newcomer...
Krystal - Holding a high place in Sakurai's poll, she could easily stand to replace Falco...
Lucario - Incredibly popular in the Pokemon world, Lucario has the "aura" of being a Brawl participant, as well as the move set and popularity...
Geno - Another super-popular character in polls, Geno would also fill in a missing "3rd party" block, even though Sakurai claims he thinks him as 1st party...
Ridley - High-ranking in polls, it seems just as likely that Ridley could be given "Boss" status in the SSE as he is to be a playable character...
AC Villager - The Animal Crossing stage is already in place, and with the AC franchise being one of, if not the, biggest Nintendo seller in Japan, it seems strange for there not to be a representative...
Oh, but of course, there is the Dojo icon issue to go back to...According to the Dojo, unless they mistakenly passed over a number, there is still another franchise to be revealed...The characters above all fit into known Brawl franchises, so what's left?
Isaac - Golden Sun? Sakurai mentioned the series on multiple occasions, and I believe Isaac's Psynergy could provide a unique move set...
Lip - Panel de Pon? Lip's Stick returning as an item appears to dampen her chances, but there is the Screw Attack item, after-all...
Takamaru - Nazo no Murasame? The one thing that hurts his chances is that he's not only from a unknown franchise, but he's fairly generic as a character as well...Hmmm...
Ray MKII - Custom Robo? I recall being surprised that he was not in Melee, with him being a unique character (a robot!) and having an excellent working move set...
Sukapon - Joy Mech Fight? Another unknown franchise, Sukapon has the benefit of actually being a unique character and being from a fighting game himself...
???Other??? - There is always also the possibility of something completely random! =)
Just my thoughts...Feel free to argue or comment on this fun speculation...