Read an interview on EW and Matt Damon said that this movie isn't a whole new Jason Bourne story, but, rather, the conclusion of Jason's identity search. Matt said we find Jason in "a very dark and tortured place," which I can totally see. Yes, he's a killing machine, but in all three Bourne films, he was also reluctant to injure or kill anyone who wasn't a bad guy and he protected quite a few people along the way. So now, knowing his past just makes it worse.
Anyway, here's the poster, behind a cut because it's big!