Windows IT Pro magazine's Russell Smith posted a positive, in-depth overview of Forefront Threat Management Gateway 2010, called "Quickly Respond to Threats with Forefront TMG."
The article's intro:
Microsoft Forefront Threat Management Gateway (TMG) 2010 offers a dynamic response to security threats, providing a variety of security technologies such as anti-malware, firewall, and intrusion detection under one umbrella....
Forefront TMG Will Be a Winner
ISA has always provided the most complete protection for Microsoft products, and Forefront TMG builds on that foundation. Sys admins will warm to the improvements on the usability front from the outset, such as setup wizards and support for Server 2008’s NAP.