"When George was filming the Phantom Menace last year, most of what he envisioned on film existed only in his own mind. What I mean is that George wanted to get the actors on film and then add most of the background and FX shots later. You have no idea what George's true vision for this film will be until you see it next May . . . Even the words uttered by the actors on screen can be altered. George can have the actors come in and redub their lines and then we can digitally alter the lip movements of the actors if need be . . . We can do almost anything. The problem remains cost.
There are certain things that George wants to see in a Star Wars film that we cannot do at this time. These incredible scenes will have to be saved for Ep. 3. By then, computer animation should be cheap enough that we can do whatever George asks us to do . . . Almost every background in the new film will be computer enhanced. It has been what George has been trying to create all the time - virtual worlds. George wants to film the actors and then put them in any context he wants to. This film is so very, very experimental. And probably, will change the vary notion of how motion pictures are made . . . George is changing everything, once again." (Source: Anonymous Lucasfilm Insider)