Merrick here...

The Powerrs That Be have hauled in Josh Zetumer to write a script for the 4th BOURNE movie. Oddly, it's not clear if his script is being positioned as a standalone, or may somehow be grafted onto material already developed by George Nolfi (OCEAN'S TWELVE, BOURNE 3).

George Nolfi, who worked on "The Bourne Ultimatum," initially came back for the fourth entry. He also boarded to write and direct "The Adjustment Bureau," an adaptation of a Philip K. Dick short story that reteams him with "Bourne" star Matt Damon.

But as that movie nears its September start date, Nolfi had to step away from "Bourne." Not wishing to slow development and keen on making "Bourne" part of its 2011 slate, Universal hired Zetumer to write a new script. It is unclear what will occur after Zetumer submits his draft or whether his script will be integrated with Nolfi's.

...says THIS piece at THR.

It should be noted that the incoming Zetumer is also developing a DUNE remake with Peter Berg.