Federated Identity is here - are you following information about 'Geneva'?  What is it?  From a well-written blog post from Bruce Kyle, here's a definition:

"A project Microsoft Code Name "Geneva" is an claims-based access model identity platform’s foundation is the claims-based access model. It is built on Security Token Service (STS) technology that we've been developing over the past few years as part of its industry effort to create a single identity system based on standard protocols.

'Geneva' helps simplify user access for developers by externalizing access logic from applications via claims, and reducing development effort with pre-built security logic and integrated .NET tools."

X Enterprise Trust Diagram 

“Geneva” Team Blog