The Bourne Legacy takes place in the same universe as the Jason Bourne trilogy, but revolves around a different, highly-lethal government assassin named Aaron Cross (The Avengers' Jeremy Renner). Bourne's exposure of Treadstone's illicit deeds motivates one of the program's co-heads (Edward Norton) to initiate a kill order, so as to remove every shred of "evidence" that could be used against his government peers in court - including, Noah Vosen and Dr. Albert Hirsch (David Strathairn and Albert Finney, reprising their Bourne Ultimatum roles).
Such "evidence" includes Agent Cross and the scientist (Rachel Weisz) responsible for altering his genetic structure, making Cross (quite literally) a super-human killing machine. The two team up in order to stay alive and seek refuge overseas. But with a multitude of government spooks on their tail, how long can the pair hope to stay alive?
Bourne Legacy co-writer/director Tony Gilroy (who co-penned the Bourne trilogy) has been keen to emphasize that this fourth installment is about expanding the breadth of the Bourne movie universe (BMU?). It's for that reason that the film's trailers and TV spots have recycled the same self-aware piece of dialogue ad nauseum ("You think Jason Bourne was the whole story?"). The idea, basically, is that whoever's watching could still be under the mistaken assumption that Bourne Legacy is a franchise reboot - and needs to be assured the film isn't a do-over, with Renner replacing Matt Damon as the eponymous character (a la Amazing Spider-Man).
It becomes tedious, having to listen to the same key bits of exposition throughout the Bourne Legacy marketing campaign. However, when you take those out of the equation, it's easier to see how an uninformed person could watch a Bourne Legacy promo and assume the film's just a direct remake. That's partly due to Hollywood's trend of rebooting (seemingly) every other recent franchise in existence, but also because much of the Bourne Legacy action is partially recycled from previous installments (rooftop foot-chases, motorbike chases set in crowded areas, etc.).
Moving past the marketing: Bourne Legacy does boast a great cast, and Renner on a hot streak after his turns in Mission: Impossible 4 and Avengers. Moreover, the film's story comes off as a logic extension of the previous Bourne movies, and sets the stage for what appear to be slick set pieces and action scenes - minus Paul Greengrass' intentionally disarrayed camerawork/editing from the previous two Bourne films (a definite plus, for some people). So that's all promising enough.
The Bourne Legacy opens in U.S. theaters on August 10th, 2012.