Well it looks like George Lucas has altered the ending to Return of the Jedi. There is a .mov available for you to have a look at. I don't want to say too much as it might be a spoiler.
As well as the ending he has again remastered the original 3 films, as well as added new scenes to the DVD release. If you want to sample some then check them out here it goes into some details but aslo has a lot of comparison picutres.