Personally I've thought for a while now that a good scenario would've been to have some sort of combination of Spielberg, Johnston, Darabont and Fincher, with no two prequels being directed by the same person. Maybe three of those guys could be the directors and the fourth guy would basically be the PT's Kasdan. Maybe it could go:

Episode I: Johnston

Episode II: Spielberg

Episode III: Fincher

Darabont could write the screenplays. Lucas would write the story, but maybe Frank would have some input. I guess McCallum would still produce. The directors would have final say on who the cinematographers would be, so for Spielberg that would obviously be Kaminski (which, seeing how his CinemaScope debut on Indy IV turned out, would work PEFECTLY).