Paramount has confirmed that JJ Abrams is reteaming with Tom Cruise to make Mission Impossible IV for summer 2011 release. (Abrams won't direct, just produce.) Cruise will star, and Alias writers Josh Appelbaum and Andre Nemec will write the script.
The thing I'd really like to see is a re-reboot of Mission Impossible more faithful to the original series. This time, with an ensemble cast like the original, instead of a single egomaniac action hero center stage.
That was the awesome thing about the original show. Each character had a job to do, but everything failed unless their tasks all intermeshed successfully. Some episodes managed to keep things mysterious and confusing until everything came together right at the end. That was the most satisfying thing.