Luigi's move were somewaht similar to his bro's and I know C. Falcon was not a clone, but they both could be delayed in updates b/c of a new moveset
Luigi's moves are somewhat similar (key word there, similar, not identical as a clone's are) to Mario's on purpose - they're brothers with similar abilities even within their own games. They'll probably be differentiated further in Brawl (if only due to the FLUDD/Poltergust options), but don't expect them to bear no resemblance to each other. But setting that aside, why would Captain Falcon get a new move set? Hes had that one in both of the previous games, and it certainly suits him. Ganondorf on the other hand it makes no sense on, since in his games he always fights with either magic or a sword (or two). Plus, as others have noted, he was intended to use a sword in Melee, as seen by the one he holds after some vs matches.
Anyway, yeah, theres no reason for clones to return this time around. Melee had them due to the time frame being forced on Sakurai & co - they had to get it out for the 'Cube's release, and didn't have time to give unique moves to all the characters. This time they got to set their own time frame, so theres no reason for them not to have individualized moves for each of the characters they select.
Zevox