I'm sure there are others that are compiling precedence against the use of the SERPA system for evaluation by their command/dept.
Here are some official/unofficial statements on the subject:
Larry Vickers: Serpas banned from training courses
Gunsite: Serpas not officially banned, but not recommended
source: Cory Trapp of Gunsite
ToddG/Pistol Training: Serpas banned as of this year (2012)
FLETC: Pending verification, Serpas are banned
Pat Rogers: "serpas suck"
Updated to add: LAPD. Since posted years ago, countless other instructors have added to the list (Defoor, Jeff Gonzales, and more). At this point it's probably easier to name the few that will still allow it.