I know theres been enough topics relating to pokemon characters already. But some people kind of throw out some really unrealistic ideas for characters like Zapados being playable. Some have good ideas like Blaziken.
Ditto really should be a playable character. We're familiar with how he can transform into other characters, and that could add a lot to the gameplay. But he doesn't have to turn into other characters on the screen, he could turn into any character in the game randomly. The player won't have control of this of course. But for each stock Ditto could be a completely different character. Think of it, in a three stock match you could be Mario, then Pikachu, then Fox.
Of course Ditto will keep his pink skin and goofy face when he transforms.
Now I say this because one time I was playing in a Soul Calibur 2 tournament, and I got to the quarter-finals. I versed a kid who used Charade, if you didn't guess hes a character that becomes anyone randomly. And that kid beat me and won the tournament.
So if Ditto really became a character, players who want a real challenge could pick him. They would have to master/know each character. And to use Ditto seriously would be an honor because that would prove you are ridiculously good at the game.
I'm adding my votes for Ditto any way I can. I hope someone else does too because he really should become a character for this game.