If they fix any of the innumerable technical errors with the 2004 versions they'll be opening themselves up for a lot of criticism. They made such a song and dance about it being a 'creative choice' that any changes would leave them with a huge amount of egg on their face.

There are loads of technical errors on the 2004 editions: incorrectly mixed audio, damaged audio elements, inconsistent colour timing, incorrectly coloured lightsabers, garbage mattes... the list goes on. Of course of none of that is taking into consideration the terrible changes hacked in there to try and make the originals fit the prequels - Lucas apparently failed to realise that it should have been the other way around.