I found this on TFN:

“George is certainly leaving stuff unchanged for a future release. Just read “THE MAKING OF STAR WARS REVENGE OF THE SITH”. It actually tells of his process of the DVDs during the production. He would go and view the DVDs in a theater to look for things that have to be improved and how Lowry Digital cleaned the films. <span class=“Bold”>He even said that in a sequence in ESB, the Bespin city would be redone for future releases so look for that.</span> I just can’t see him looking over major errors like the lightsabers especially if he watched them in a theater. But just read the book and you can tell that he is saving many changes for a final release. I believe the 2007 DVDs or Hi-def DVDs will be the final absolute version.”

“The original Star Wars was a joke, technically,” Lucas commented. “I had to make a movie that normally would have cost ten times what it finally costs, and so I had to cut corners and cheat and make it kind of fuzzy so you couldn’t see what was going on. In addition, most of twhat we did on Star Wars, in technical terms, had never been done before. It was all prototype stuff and, consequently, it wasn’t very good. But Star Wars worked as a story, and that was what I cared for. Same with this movie. As long as the effects were good enough that people wouldn’t be aware of technical flaws or inadequacies, then the story was being told. As long as it didn’t interfere with the story, it was good enough for me.” - Mythmaking: Behind the scenes of AOTC