How to Configure ISA SSL Bridging for System Center Configuration Manager Internet-Based Client Management
Some new documentation is now available on Technet: How to Configure ISA SSL Bridging for System Center Configuration Manager Internet-Based Client Management (http://go.microsoft.com/fwlink/?LinkId=122350). This has been a joint collaboration between the ISA Server product group and the Configuration Manager product group to provide guidance on how to configure the two products to work together to support Internet facing clients.
This provides a higher level of security for Internet traffic than the alternative method of tunnelling, or tunneling if you're in the US :). With ISA bridging traffic from Internet clients is authenticated and terminated at the ISA Server, inspected, and then new SSL connections are made to the Internet-based site system servers. This is as opposed to tunnelling, where the traffic from the Internet clients is forwarded to the site system servers without termination, so it cannot be inspected for nasty content.