Some good reading here from the Microsoft Exchange team on the end of life of Threat Management Gateway (aka TMG). Certainly at edgeNEXUS we’re seeing more and more interest in edgeNEXUS specifically as a Reverse Proxy / TMG replacement, particularly as it’s inherently part of our product, allowing our clients to both load balance their Exchange deployments AND take care of the Reverse Proxy element without requiring any additional add-ons
Life in a Post TMG World – Is It As Scary As You Think?