^^My main interest in SW 7 (thru 9) would be to see if they can fix what they broke (although Revenge of the Sith wasn't awful).
Disney didn't break anything! Lucas is just going to be a rubber stamp, there's no way Disney paid him 4 billion dollars just to let him frak it all up again.
To Disney, Luke Skywalker = Snow White = cash cow to milk for all eternity. They made a Snow White movie in 1937, which didn't stop them from recasting the role 75 years later for a TV series. Luke and the gang are going to be like that. The role will be recast in the forseaable future and keep being recast when we're all dead & gone & people watch Star Wars on holodecks.
But Darth Vader is an even bigger brand name than Luke, so I have no doubt that a reboot of the prequel, which can hardly help but be an improvement, is an inevitability, since that's the simplest way to revive Darth's brand as an excuse to make more $$$ off the guy.