So where does the story go from here? Speaking to Deadline, Gilroy says that the script involves other members of the Treadstone project, and will probably follow a fellow soldier who's been turned into a merciless killing machine. It's not an ideal solution, but it's probably a better idea than recasting the role which is iconically Damon's, and at least there's precedent: Bourne has fought enough fellow Treadstoners in the first three films that audiences should at least accept the idea of there being some interesting stories to hear. It also leaves open the possibility of Damon returning to the films in the future should he wind up needing some kind of massive payday in a few years.
And thus, agents around Hollywood are no doubt beating down Gilroy's door trying to get their client in for a reading. Damon was already fairly well-known before he did Bourne, obviously, but one has to wonder if Universal won't take a Spider-Man page from the playbook and get a young, inexpensive actor signed up for a multi-film deal. So long as it's not Shia LeBeaouf, I'm interested.