The August/09 American Rifleman (p. 30) has a couple of interesting facts about the M&P that I hadn't heard:

* Detroit PD is switching (from whatever they used previously) to the M&P. They're ordering 5000 M&P .40 pistols, and 350 M&P AR15 rifles.

* The article says the M&P pistol (no caliber breakdown) has now been adopted by 505 U.S. police departments.

In the interview, the Detroit Chief said they adopted the M&P pistols because they passed their internal review process, they liked the customization capabilities of the pistols, and they liked S&W's warranty and service.