Well it would be a pretty cool idea, so lets say they keep 24 characters. Who makes it in, in your mind. Here is my starters and unlockables.

REMEBER THIS IS FOR FUN...NINTENDO HAS NOT CONFIRMED A GAME EVEN LIKE THIS

Starters
Mario
Link
Kirby
Donkey Kong
Samus
Meta Knight
Fox
Captain falcon
Pickachu
Marth
Zelda
Peach

Unlockables
Bowser
King Dedede
Ganondorf
Luigi
Yoshi
Pit
Ike
Ness
Ice Climbers
Mr.Game&Watch
Olimar
Sonic (3rd Party Deal Again Anyone?)

I love this idea, to bad it will probably never happen.