It is said that Lucas will release this boxset this November, along with a prequel boxset for current owners of the OT DVDs. There are many changes, including to ones made to the 2004 DVDs. Most of the info come from theforce.net, and below are the details:
THE PHANTOM MENACE:
New Digital and Audio transfer
The Changes:-
1. Some of Jar Jar Binks's lines have been removed and changed
2. Improved CGI backgrounds in certain scenes
3. Yoda's facial expressions are now mostly CGI
Features:-
Slightly altered audio commentary
Deleted Scenes
Original Theatrical Trailers
TV Spots
Duel Of The Fates Music Video Featuring John Williams
Collection of Photographs of Cast,Crew & Production
ATTACK OF THE CLONES:
New Digital and Audio transfer
The Changes:-
1. The Jedi Raid on the Droid Control ship has been completed and added to the film (completed footage filmed during episode III)
2. The noises Yoda makes while fighting Dooko have been changed
3. One of C-3PO's lines has been changed and another one has been removed
Features:-
Slightly longer audio commentary (beacuse film will be slighly longer)
Deleted Scenes
Theatrical Teasers
Launch Trailer
TV Spots
Collection of Photographs of Cast,Crew & Production
REVENGE OF THE SITH:
The Additions:
1. A scene has been added where Yoda explains to Obi-Wan who erased Kamino from the Jedi files and that he is going to await contact on the planet Dagabah (filmed during episode III)
2. An extended battle on Kassakk
Features:-
Audio commentary
Deleted Scenes
Theatrical Trailers
TV Spots
John Williams Music Video
Collection of Photographs of Cast,Crew & Production
EPISODES I-III BONUS DISK:
'From Dreams to Reality' (in depth making of the Prequel Trilogy including interviews with George Lucas, Rick Macallum, John Williams, Ewan Mc Gregor, Natalie Portman, Hayden Christian, Samuel L. Jackson, Frank Oz, Anthony Daniels & Christopher Lee) It runs at about 2hrs 40mins
Preview of 'Clone Wars 3D' television series
Blooper Reel (over 6 & a half mins)
'Extending the Saga' (an in-depth look at how the Lucas's orginal plot for Star Wars has changed)
'CGI'ing the Movies' (an in-depth look at how CGI has had a dramatic effect on the Prequel Trilogy)
'Saber Fights' (A documentary regarding all the lightsaber fights in the Prequel Trilogy. Presented by Nick Gillard)
Exclusive DVD-ROM Content
A NEW HOPE:
New Digital and Audio transfer
The Changes:-
1. The 'Imperial March' music has been added to Vader's first appearence
2. When Obi-Wan is talking to Luke about his father Anakin's theme music can heard in the background and when Obi-Wan starts talking about Vader it changes to the Imperial March
3. Luke's lightasber is blue throughout the film
4. In several scenes where creatures are seen (e.g. The Cantina) some have been replaced by creatures seen in the prequels
5. The bleeding arm Obi-Wan slices off a creature in the Cantina does not have blood seen on it
6. Just before the Death Star destroys Alderaan there is a new scene added where different places on the planet can be seen along with Bail Organa & his wife. Shots include Bail being warned of the Death Star, the destrution on the planet which includes massive earthquakes, fire and peopele frantically trying to escape, you see Bail looking up into the blackend sky before the planet totally blows up (filmed during episode III)
7. The Death Star's computers and screens have been improved
8. The opening text crawl has changed (details unknown)
9. Luke looks upset when Biggs dies and he sheds a tear (all CGI & PRT)
10. The duel between Vader & Obi-Wan is roughly a minute longer as there are more shots of the lightsabers clashing and them moving about (done using CGI, PRT & Stuntmen playing Vader & Obi-Wan). Music has been added to the scene as well (deatails unknown yet)
11. Just before the medal ceromony at the end, a scene has been added where Vader lands his damaged ship on Coruscant to meet Palpatine. They discuss the destruction of the Death Star, Obi-Wan, Luke & finding the Rebels. This is the first time Vader relises his children are alive and that Luke destroyed the Death Star (filmed during Episode III)
12. Vader's mask eyes remain black throughout the film
13. John Williams has rescored the music for some of the scenes (details unknown yet apart from changes 1 & 2 in this list)
Features:-
Alterd Audio Commentary (because of changes)
'A Completed Saga' (interview with George Lucas about the new changes to A New Hope, why he made them and comparing them to the previous versions)
Deleted Scenes
Theatrical Trailer
TV Spots
Collection of Photographs of Cast,Crew & Production
THE EMPIRE STRIKES BACK:
New Digital and Audio transfer
The Changes:-
1. Some shots where Taun-taun's can be seen have been changed so the Tuan-tuan's have more movement and look more realistic
2. While the battle of Hoth is going on Imperial ships land near the Rebel base and a few more shots of ships flying and being destroyed have been added
3. Some of the views of Bespin (for example the background where Luke is holding on to the metal poles beneath a building) have been improved to look more realistic and ships can be seen flying around in the distance
4. A scene has been added where Yoda is teaching Luke how to fight with a lightasber made possible by Luke wearing a helmet while training (a stunt double plays him)
5. The Wampa scenes have been edited and restored into the film as well as new scenes added. We see a Wampa being brought into the Rebel base and locked into a room with other Wampa's. Later C-3PO knocks the sign off the door the Wampa's are behind stating their there and when the Stormtroopers enter the base they open the door only to be attacked by the Wampa's who then can be seen escaping as the Millennium Falcon blasts off out of Hoth
6. Lightsaber effects improved
7. The sound of Luke's lightasber turning off as he exits cave has been removed
8. Some of Yoda's facial expressions have been improved beacuse of CGI
9. (John Williams has rescored the music for some of the scenes (details unknown yet)
RETURN OF THE JEDI:
New Digital and Audio transfer
The Changes:
1. In the battle on Endor more Ewoks and Stormtroopers can be seen fighting and dieing and some parts of the battle have been edited out, members of Han's team can be seen fighting as well (these scenes were shot during the production of Episode I, 7 years ago)
2. Vader uses the force to reclaim his lightasber after he throws it at Luke and the sound of him turning it on again has been removed
3. The lightasber duel between Luke and Vader is slightly longer (just more shots of clshing lightsabers)
4. The lightsaber effects have been improved
5. Vader has a flashback of Padme after his talk with Luke when he first meets him on Endor (filmed during Episode III)
6. Kassykk & Utapau have been added to the end celebration scenes
7. Some of Yoda's facial expressions have been improved beacuse of CGI
8. Boba Fett's scream has been changed
9. Chewbacca's Tarzan call has been removed
10. John Williams has rescored the music for some of the scenes (details unknown yet)
Features:-
Alterd Audio Commentary (because of changes)
'A Completed Saga' (interview with George Lucas about the new changes to Return of the Jedi, why he made them and comparing them to the previous versions)
Theatrical Trailers
TV Spots
Deleted Scenes
Collection of Photographs of Cast,Crew & Production