So assuming the video leak & Reno/MarkMan are 100% correct...
Which leaves 6 spots for returning Melee characters. I'd guess...
Falco
Luigi
Ganondorf
Captain Falcon
Mr. Game & Watch
Marth
Returning = 14
Mario
Link
Kirby
Pikachu
Fox
Samus/ZSS
Zelda/Sheik
Bowser
Donkey Kong
Yoshi
Peach
Ice Climbers
Ness
Jigglypuff
Newcomers = 15
Pit
Wario
Ike
Pokemon Trainer
Diddy Kong
Meta Knight
WW Link
Snake
Lucas
Sonic
King Dedede
R.O.B.
Olimar
Lucario
Wolf
Which leaves 6 spots for returning Melee characters. I'd guess...
Falco
Luigi
Ganondorf
Captain Falcon
Mr. Game & Watch
Marth