Digital Cinema version had Padme holding Anakin’s prosthetic hand at the end. 35mm did not. I’m relatively sure that was the only difference between those two versions. I’m still kicking myself for not going to see the digital version when it was playing at the National Amusements / Multiplex theater in Merrifield, which was also the closest theater to where I lived in Falls Church (it was the only theater in all of Virginia showing it that way per starwars.com, and one of only a hundred in the whole country). I saw AotC on 35mm opening day in downtown DC intending to see it again in digital, but the Merrifield theater had swapped it out for Scooby-Doo before I was able to.
I’m 99% sure that the scene extension of Anakin’s confession to Padme about the Tusken slaughter wasn’t added until the dvd, not the dcp. I know dvdactive’s comparison said otherwise but I’m almost positive they’re wrong. I was actually just starting to post on message boards that summer (TFN, which I thankfully abandoned not long after finding this wonderful place), and I don’t recall anyone mentioning anything except the hand-holding in the final scene.
As noted, the IMAX version was cut down because the 15/70 projector reel platters couldn’t hold more than 120 minutes of film at the time. I never saw this version (it came out within only a few days of the dvd IIRC, which I never thought was a very good business decision but whatever). Some people who saw it said the edits actually improved the pacing of the movie.
The only major difference on the blu-ray I remember hearing about is the re-editing of the Yoda/Dooku fight, specifically when Dooku force-…collapses(?) that structure next to Anakin and Obi-Wan so he can make his escape. Youtube was a thing that existed by 2011 and I remember someone posted a simple camera recording of their tv for this scene. Other than this change, I’m assuming it’s identical to the dvd version in terms of content. The movie was given a new color grade that makes it look significantly different from the dvd, unlike RotS.