Lets see. Characters that should be in the next Super Smash Bros., assuming all the ones in Brawl stay in including Sonic & Snake.
Lets first start with some of the ones that were found in the code but left out for some reason.
1) Dixie Kong
2) Plusle & Minun
3) Mewtwo
4) Toon Zelda/Toon Shiek (or Tetra) assuming that the same Young/Toon Link is in it.
Now onto the 1st & 2nd Party Characters
1) Isaac from Golden Sun
2) Lyn from Fire Emblem or Eirika from Fire Emblem Sacred Stones
3) King K. Rool from Donkey Kong
4) Krystal from StarFox
Continuing on, some 3rd Party Characters I'd like to see
1) Geno from Super Mario RPG:Legend of the Seven Stars
2) MegaMan from MegaMan Classic
3) Sora from Kingdom Hearts
4) Knuckles from Sonic
5) Tails from Sonic
6) Gray Fox from Metal Gear Solid
7) Laharl or Etna from Disgaea
I know that Laharl or Etna would be unlikely, but it would be awesome none the less.
Alternate Costumes I'd like to see if Alt. Costumes are to be incorperated.
1) Mario - Dr. Mario, ShineSprite Shirt/Sunglasses Mario
2) Luigi - Mr. L
3) Peach - Daisy, Rosalina, Sunshine Peach
4) Bowser - Dry Bowser
5) Donkey Kong - Funky Kong
6) Yoshi - Boshi (if Geno is put in)
7) Link - Fierce Deity, Village Link, Zora Armor, Magic Armor
8) Ganondorf - Wind Waker Outfit, Ocarina of Time
9) Kirby - Waddle Dee, Waddle Doo
10) MetaKnight - Dark MetaKnight
11) Olimar - Louie
12) Pikachu - Raichu
13) Pokemon Trainer - FR/LG Female, G/S/C Male/Female, R/S Male/Female, E Male/Female, D/P Male/Female, Pl Male/Female (Diff. Voices for Females)
14) Snake - Raiden
15) Sonic - Shadow, Silver, Metal Sonic
16) MegaMan - EXE, X, Model X, Legends
17) Sora - Roxas, Riku, KH1 Sora, Tron Sora, Halloween Town Sora
18) Plusle & Minun - Pichu Bros.
19) Isaac - Felix from Golden Sun Lost Age
20) Knuckles - Metal Knuckles
21) Dixie Kong - Tiny Kong (Donkey Kong 64)
22) Krystal - StarFox Adventures, StarFox Command, StarFox Assault