I was thinking about forbrawlbattle's prediction and the 35 man roster, and it occured to me. What if some secret characters were only unlocked if you had the corresponding Wii game to go with it. What if Miciah was only unlocked if you had a Radiant Dawn save, Paper Mario with Paper Mario, Luigi if you had beaten Galaxy, and Dark Samus if you had Prime3. Could you imagine a marketing engine so wicked, yet so amazingly perfect?
On a more positive note, who is the most likely character that was a 'requires patience' trophy in Melee?
Meowth - Beat all-star mode with every character. Good pick as a rival to Pikachu.
Mew - Clear all-star mode on Hard or Very Hard. Good replacement for MewTwo's moveset
Celebi - See celebi after unlocking all levels and characters. More luck than patience.
Tom Nook - 1000 coins. Not much patience.
Paper Mario - 450 meters on Home Run Derby. Not all that hard.
Diskun - Earn all bonus. Horrible idea for a character
Unown - 5000 meters of total distance for all characters in home run derby. Horrible idea for a char.
Sheriff - Beat all Targets with total time under 12.5 minutes. Superbly WTF character, even predates Game & Watch, but uses guns. I don't know how Sakurai would get around that, unless he just includes them in a super pixelated form.
for pokemon, you would have to assume that new character was added in after that video shot was taken.
P.S. I'm starting to think the Neogaffers only had access to a non-final build. According to Mr Game & Watch, a few characters that were cut were recently added back in. K. Rool is probably the first thing that comes to mind. He said they were almost finished with his moveset. K. Rool makes sense because the game ought to have 4 kings for a subspace emissary mission. 3 doesn't make much sense. We have Bowser, DeDeDe, and we will have Ganon. K. Rool perfectly rounds this out.