As an official Star Wars nerd (my sons nursery is star wars themed completed with a "the force is strong with this one" above the crib), may I weigh in and say I am not sold on this.
As much as Lucas fumbled the first 3 episodes, his input is key because like it or love it, it is his baby. You can't screw with Star Wars too much. You stick to the same directorial style that has already worked, and keep the same vibe, but you enhance the WRITING and CASTING.
I could quite possibly direct a Star Wars if those two most important factors were already handled.