Of course, that would mean that the episode numbers of the OT would have to be changed to I, II, and III, but it's an intriguing idea. The sequel trilogy could have intertwined a new sequel story with the story of the prequels, showing the latter in the form of flashbacks or something similar. That would allow for a presentation of just the main story of the PT and make it possible to keep a lot of the mystery of the Old Republic and the Jedi that the PT as we have it failed to do, but still spreading it over three episodes.