Hi,
There is not much that you can pull from the SEPM about GUP.
How to search for the clients that act as Group Update Providers ?
http://www.symantec.com/docs/TECH96094
Troubleshooting Content Delivery to the Symantec Endpoint Protection client
http://www.symantec.com/docs/TECH106034
This tool can be used to monitor the status
SEP Content Distribution Monitor / GUP monitoring tool.
http://www.symantec.com/docs/TECH156558