I know it's been mentioned here before, considering how much footage they shot for the prequels, more than the OT movies, they really should just re-edit them completely from scratch.
You could change A LOT, by combining the truly best takes and scenes, rescore, redo all the FX (especially considering all the greenscreen and bluescreen used in 2 and 3.) They could even drastically alter the plots.
Can't Disney make new edits, just like Lucas did, just far more extreme and higher budget?