pittrek said:

Here you can find all found changes done specifically to the 2011 release : http://plus.google.com/photos/102542760950977079734/albums/5647165429128459745?banner=pwa

He was asking about RoTS.

It seems the following two differences may be possible, but I don't know for sure (from wikipedia):

edit: also, he said significant. So, the answer is probably no. Also, is it just me or is it impossible to put text *under* a manually added quote box like the one below?

The scene where Obi-Wan encounters General Grievous on Utapau and the Clone Army arrives has been altered, adding dialogue from the troopers as they land on platform

The scene transition from Padme's ship to Vader on Mustafar has been changed from a straight cut back to a wipe, restoring the original theatrical release.