I saw it tonight and actually enjoyed it.
I find all the Bourne movies kind of "cold" straight-forward pics, without a lot of character dev or emotion, so more of the same (fitting my expectations) didn't bother me at all. I think maybe the only thing that the Matt Damon pics had going for them was the ongoing mystery of who Jason Bourne was, and so that mystery isn't really part of this movie, it was just a pretty linear action film... although they tried to mix it up by inserting a few edits from the last Bourne film, to show you where things fell in terms of time sequence (the action here actually starts before the end of the last movie).
I also wasn't really enamored with Jeremy Renner in MI:4 but here he did really really well -- believable, solid, capable. He carried himself just right in this film.
I mean, really, once things got going, it was just a bunch of bad-ass chase/fight scenes. My only gripe is that the movie just kind of ends after the last fight scene without any kind of feeling of "wrap up" etc.
It's also not clear what happens next. At least Mission Impossible has going for it the idea of "quests" or jobs to be accomplished as part of Ian's employment. Jason Bourne had going for him the quest to figure who he is. Here, Aaron's task has been basically to stay alive and get off the meds they've been feeding him. So if they do another film, it's gonna have to actually find a direction for itself.