Heard about it at the techEd. Came across nice tutorial in the WHIDBEY release notes. Indigo as MSDN says is the new standard for building and running connected systems. Like previous distributed technologies like web services, Remoting, MSMQ etc, it is a Service oriented programming model built on .NET framework. Will be available for Longohorn natively, and requires some SDKs( right?) for win XP and server 2003 development.
Sounds like next big thing!