The fourth Bourne-film is being written by Josh Zetumer (‘Dune,’ ‘The Infiltrator’). Originally, the sequel was supposed to be written by Bourne Ultimatum writer George Nolfi, but he’s committed to adapting the Philip K. Dick short story ‘The Adjustment Bureau.’
Apparently, Zetumer has been comissioned to write a brand new script. Apparently, once its finished, it’ll be used, or integrated to the script that already exists (and written by Nolfi).
Universal is aiming for a 2011 release date for the fourth film. I’m a huge fan of the series and have been since the first. Though it was Paul Greengrass’ contributions in the last two that really made this a solid franchise.