Also:

1) 35mm is not the best resolution (70mm and 65mm are).

2) 1080p remaster can be perfectly good if done right (the 2004 one wasn't).

3) There is absolutely no way they could make a real 4K transfer of Ep II & III, because those were both shot digitally with 1080p resolution, so there will never be any natively higher resolution of those two films and of episode I neither, because while shot on 35mm, most of the film has got some CG in and for that they scanned the film at 2K, so all the CG shots in ep I have a maximum of 2K resolution...

EDIT: Akwat Kbrana beat me to it...