Just to add to this, "DvdAnswers.com" a great site that helped a lot when creating this thread, has changed its url to "DvdActive.com" http://www.dvdactive.com
Go there and look up "Star Wars" and you'll see they have extensively revamped their articles on the Star Wars DVD releases. They have two reviews for each movie, plus reviews of the 2006 editions compared to the 2004 and comparing with the 1997 Special Editions. They even have an article detailing the changes made to the prequels (all three were altered from their original theatrical releases before coming to dvd, though Episode III only changes the transition from one shot, and the one shown in select digital theaters of AOTC matches the DVD version while it differed from the IMAX cut and the film version, the latter of which most theater viewers saw in 2002).
Also, there's a nice thread about the 2006 dvd release (which is still available, btw, even though the "limited release" timeframe has long passed):