Star Wars and Spielberg!

In an interview on StarWars.Com with J. W. Rinzler, author of The Making of Revenge of the Sith, he revealed an interesting bit of trivia for Star Wars fans:

Steven Spielberg was involved in some of the animatic sequences in the film. Can you tell us about that?

As George explains in the book, he gave Spielberg a few scenes to play with at the animatics stage: a bit of the Mustafar duel, and Yoda's duel with the Emperor, along with a couple of others. How much of Spielberg's contribution made it to the final film, only Lucas or Spielberg could say, particularly as George revised and reinvented every scene in the film so extensively in editorial.