See, what Lucas doesn't understand about Indy & SW, is Indy(Harrison Ford) is what sells Indy, and the story of SW is what sells SW. By having Shia as a continuation of the Indy adventures will kill the series, because people are plopping down their 10 bucks to see Harrison Ford, plain & simple.

With the PT, Lucas was able to get away with a new cast, because the story tied to the OT, and how Darth Vader came to be was the hook that kept us waiting for 3 movies.

It would be like having Back to the Future IV, and not having Michael J Fox in it, and some new guy flying the Delorean all around with new adventures, nobody would care!