I think that this topic belongs in the Disney Board since it focuses on the idea of shows being aired on one of their channels, so I'll go ahead and move it there.
Considering that Powerpuff Girls and Foster's Home for Imaginary Friends are Cartoon Network original series, I seriously can't see them airing on any Disney Channel. Cartoon Network wouldn't want to let their original shows air on a differnet channel and I don't think that they could buy the rights from Cartoon Network either. Even if they could, just because Craig McCracken is working on a series for Disney doesn't mean that they'll go out of their way to get the other shows he's worked on. I don't think that they'll even associate him with being the creator of other shows from a different network, regardless of their popularity. Besides that, I don't think that Disney would be interested in getting shows that ended years ago based on how they treat their own shows once they've aired the last episode.