A SW film directed by Mel Gibson? Yeah ... not going to happen. I think Mel's a good director, but there's no way in the sixteen Buddhist hells that Disney's gonna allow a man with his reputation to ever direct a SW film.
As for Sam Raimi ... God, I hope not. In the '80s and '90s? Sure, I'd have loved to have see him direct a SW flick. These days, though? NO.