check out this:
http://www.blackberryforums.com/bes-...-policies.html
However, from my experience, the Enterprise location tracking still does not work reliable, which seems to be a problem of the BB device software. Instead of the server asking the device at regular intervals for its (last known) location, it is the job of the devices to submit their location, which they only do random.
The only thing you AFAIK get is shorter batterylifetime if you enable this function.