Microsoft Passport is essentially a flop. However, Microsoft's new identity system, Infocard might take actually take off. You can get a deeper look into how it works now by heading over to the MSDN Magazine site and reading two articles. The article "A First Look At Infocard" (from the April 2006 edition of the magazine) gives a good overview. The second article "Step-by-Step Guide to Infocard," (from the May 2006 edition) delves into much more detail.