I just read an interesting quote from a certain person over at the steve hoffman forums.

This is concerning the original restoration for the 2004 release:

I was told point blank at ILM that Lucas kind of didn’t really care that much about home video, and he was mainly concerned with whatever project he was on at the moment. They told me they had considered remastering the theatrical versions AND the revised versions simultaneously, but there just was no time available to do it because Fox demanded a pretty stringent deadline. Money was part of it, but it was more about time than money.