Could the estate allow it, or would Lucas write into his will "not even over my dead body?"
Hey, whatev. If we can at least get the OOT mastered in HD someday (a feat well within the realm of the possible) then I can live without Episodes VII through IX. It would be hard enough to fit it into continuity, although they have left themselves a one hundred year gap before the Legacy comics start.
While I'm on that subject, no, I don't think we're ever going to see something like a reboot happen with Star Wars. This only happens when the franchise is both creatively bankrupt and not still controlled by the guy who started it 30 years earlier. Even when Lucas is gone, the most unexpected thing that might actually happen is what we're all on this website for. But I have a feeling that could happen much sooner.
It's been redone in its own way anyway, with alterations to the original and retcons in the prequels. Really, I think that's the key difference between Star Wars and the other franchises.