Auth and Auth in the Cloud

I have been developing on the Windows Azure platform for the past 8 months or so. One of the more interesting reads I have had is a developer white paper on the .NET Access Control Service, one of the components of the Azure Services Platform. It gives a great overview building Claims-based applications and dives into a sample application. I have to say that I think Microsoft is headed in the right direction to delivering Identity Federation in the cloud, making the migration of enterprise applications to the cloud more of a reality.