Based on the evidence, it looks like this is how they're branding catalog Best Picture winners going to Blu-ray from here on, with new extras. Braveheart and Gladiator hit on September 1st, with Forrest Gump following on November 3rd.
Braveheart features over two hours of new features (my comments in brackets):
Interactive Timelines
Three distinct timelines featuring a combination of video, images, text and audio that can be accessed linearly or randomly.
Production: A comprehensive chronology of the motion picture from conception through theatrical release, from a behind-the-scenes point of view.
Historical: Chronological modules feature Scotland's greatest patriot, along with historical places, figures and events surrounding his life and struggle.
Fiction: A comprehensive timeline identifying the chronological events of the film.
[this appears to be a PiP feature you can turn on and off]
Braveheart: A Look Back
Features new interviews with members of the cast and crew reminiscing about their experiences making the film and its enduring impact on cinema.
["holy shit did everyone make a lot of money on this movie, and everyone keeps buying it!"]
Smithfield: Medieval Killing Fields
Relates the remarkable history of Smithfield, which for centuries was regularly filled with the roars of crowds, regal fanfares and rowdy games. Smithfield is also known as the site of William Wallace's execution, along with other terrifying spectacles when heretics, rebels and criminals were put to death.
[a better than History Channel look at historical fact]
Battlefields of the Scottish Rebellion
Two major Scottish battlefields, Falkirk and Bannockburn, will be presented as 3D models that can be explored for further investigation into the military strategies and timetables employed in each. Topography, weapons, troop movements, and leadership data can also be accessed. An alternate playing mode will allow the story of each battle to unfold in an "automated" fashion, much like the interactive dioramas displayed at historical site museums around the world.
[so, 3D-modeled Battlefield Porn]
Gladiator features both the Theatrical and Extended Cuts through seamless branching on the same disc and over four hours of extras, most of which at first glance appear to be duplicated from previous releases, including both commentary tracks. The press release notes "but not limited to," so I expect new extras to be added before release. Gladiator is a two-disc set and no further details are available on Gump at this point.