Completely declone Ganondorf, give all existing A attacks and B attacks to Black Shadow. Black Shadow was for a while the main villain of the F-Zero series and F-Zero deserves a villain rep. Besides, Black Shadow is a favorite in the USA because of the Falcon Punch video.
Falcon Punch --
http://www.youtube.com/watch?v=FFtw7qW7Vcw
Remake a completely new Ganondorf to use the Sage's Sword from Twilight Princess. Instead of broad sweeping strokes like Ike, Ganondorf will utilize a more stab oriented attacks, punches, kicks, and of course dark magic. However, if a new Zelda game is iterated before SSB4, then the model and moveset should be based on the new Zelda game.
Add Lyn or the future lord of the as of yet unplanned FE12 for a third FE representative.
Add Little Mac, but remodel the one used in Brawl. Stupidly enough, Sakurai must have thought that Little Mac was a buff boxer dwarf. The Little Mac character should be completely true to the original Punch-Out!! This means that Little Mac is about the same height and is slightly heavier than Marth. Little Mac can be considered a lightweight boxer who competed in the heavy weight championship in his game. Basically, Little Mac was outclassed as a boxer in the league he participated in. Little Mac should be on the weaker, but more combo oriented side. His Up B should be a signature uppercut which should be one of his more reliable killing blows.
Add either Dark Samus (Metroid Prime in disguise in the corrupted Phazon Suit) or one hunter. Dark Samus would be faster, but less powerful. Dark Samus would also not be a clone of Samus. Instead of Charge Shot, Dark Samus would use a Phazon Cannon. Hyper speed dash instead of missles. Screw Attack would be phazon powered and be a single hit, and Down B, I have no idea. Or, if the next Metroid storyline is developed, the new villain can be a possible SSB4 character. The Metroid Prime series ended with the third, which was released almost a year ago. It's likely that the next storyline is in production.
I also hope there is a single unlockable costume for each character in SSB4.
Mario: Dr. Mario (Dr. Mario series)
Luigi: Mr. L (Super Paper Mario)
Peach: Strikers/Golf/Tennis Uniform
Bowser: Rookie (M&L: Superstar Saga)
Wario: Original (Wario Land series)
Yoshi: Yoshi Hatchling (Paper Mario: The Thousand Year Door)
Donkey Kong: Funky Kong (Donkey Kong Country)
Diddy Kong: ???
King K Rool: Kaptain K Rool (Donkey Kong Country 2)
Kirby: ??? (Not sure how this can work out, since Kirby would absorb and make new hats anyway. Perhaps access to a custom color Kirby feature, where you can custom color Kirby from a selection of colors?)
Meta Knight: Meta Samurai (Kirby Super Star or Quick Draw minigame)
-- Seen in the middle of these sprites:
http://www.geocities.com/eight_ball_comics/metaknight.gif
-- Or Quick Draw:
http://www.spriters-resource.com/nintendo/kirby/nmid/display.php?file=quickdraw.gif
King Dedede: Quick Draw Costume as seen in above link?
Pikachu: Pichu or Raichu (Tough to program, considering Pichu would make Pikachu's size smaller?) Possibly additional hats to choose?
PKMN Trainer: Female Trainer (Pokemon FireRed, LeafGreen)
Lucario: ???
Jigglypuff: Wigglytuff? (Tough, since Wigglytuff is bigger) Additional hats to choose?
Mewtwo: Armor Mewtwo (Pokemon: The Movie. The armor was theoretically used to restrain Mewtwo's power)
Samus: Zero Suit Samus (No more Final Smash shenanigans and armor throwing during matches?)
Dark Samus: ???
Link: OoT Link (Ocarina of Time)
Zelda/Sheik: OoT Zelda/Sheik (Ocarina of Time)
Ganondorf: OoT Ganondorf (Ocarina of Time)
Toon Link: ???
Snake: Old Snake (MGS4)
Just a few ideas for you guys to conisder...