All of you Bourne fans have probably already heard the rumors of a 4th film in the works. IGN had an article up of Damon and Greengrass denying a movie being in the works; however, unlike the past, they are no longer saying they are against a 4th film.
Damon stated after the 2nd film that he would be done with the character after the 3rd and every consecutive interview about a 4th film has been quickly shot down. This is exciting to think the two might work together to keep the series going.
IGN: The Bourne Reality Check