Here are two threads about the differences.
http://originaltrilogy.com/forum/messageview.cfm?catid=9&threadid=1765&STARTPAGE=1
http://www.dvdanswers.com/index.php?r=0&s=8&c=29
The 70mm and SE contain a lot of little extra lines of dialogue. The 70mm would have been completed before the 35mm, so these lines were deleted or replaced for the 35 for some reason.
But as far as I know no one has documented the music changes .... which would come in really handy right now.
As far as the CE goes, rendering it out in VideoJPEG resulted in some oddness - every edit point was suddenly off by two frames, or between one and eight frames. This made all the careful compositing and FX work I'd done now useless and screwed up (as even the still frames were suddenly on the wrong frame.)
It was a simple matter to fix the less complicated edits, like the carbon freezing chamber, so I'll be rendering those out in videoJPEG, but for my own convenience the other edits (where the DV artifacts were less visible) will remain in DV form. Shouldn't make much difference as the major sins of the DV version will be fixed.
I also fixed Vader's lightsaber a bit more in a few shots where people had complained it wasn't bright or contrasty enough on the '04 DVDs.
What's going to be a real bitch is syncing up the audio though now. I guess I'm going to have to render out the entire damn movie again straight from the test DVD, and sync to that.
Again.
Onward and upward! This is turning out to be more complicated than I thought, but at least I know what to do if I ever have to do this again.
Haven't even thought about the menus yet.