This is not only an update for TMG 2010, this is a great enhancement on some of the features available on TMG 2010. Download TMG 2010 SP1 from:

http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=f0fd5770-7360-4916-a5be-a88a0fd76c7c

…and make sure to take a look at Richard’s article about SP1 new features at:

http://www.isaserver.org/tutorials/Whats-New-Forefront-Threat-Management-Gateway-TMG-2010-Service-Pack1.html

Cheers and enjoy SP1 !!