Once again, I am conflicted between my emotional and logical side.
Emotional: I would love to bring him back. he is a great character, one of my favourites, if not my favourite. Seeing how he is recieved by the other adults after his sentence would be interesting.
Logical: 1. The series has shut down for good, so there isn't really any chance... Still, there's no harm in speculating.
2. What sort of story would he lead, now that he has been redeemed as no longer being a villain? Alot of people think of Rinkus and Sierra returning too, creating some sort of conflict, but we don't actually know what happened to them in the end. For all we know, the blast from the smoking mountain could have killed them.
Also, just a side-note, if this did happen, and Michael York did not reprise his role, who could? Who could replace him as a voice-actor? My money would be on Tim Curry, Alan Rickman or Christopher Lloyd. Or maybe Jeff Bennett, if he did a voice similar to Ozzy from number II, but less deep.