I think if Lucas is going to change anything to improve the original Star Wars trilogy further he should improve some of the duff effects in all 3. 3PO looks too false at the arrival at Mos Eisley. In Empire the stop motion AT-ATs and speeders look crap and asteroid chase suffers from blueing of the dark elements. Also some effects in the Ewok battle are iffy. Like the speeder getting wrapped around the tree. One thing I'd put money on, though is the removal of the visual of Han cutting open the TomTom. I bet Lucas replaces it with Han making Luke a nice piping hot bowl of Readybrek.