Kim Cameron is an icon and thought leader when it comes to identity. As we’ve had some recent press announcements regarding our identiy direction his blog has become a must read on identity futures in MS products.
You might also want to check out InfoCard. It's an interesting product that's getting some great coverage over on Kim's blog, as well as some other blogs he links to. I highly suggest checking it out.
You may also want to check out the following white papers.
The LAWS OF IDENTITY
The key to this site: an introduction to Digital Identity - the missing layer of the Internet.
The IDENTITY METASYSTEM
A proposal for building an identity layer for the Internet
INFOCARD DESIGN DECISIONS
The design decisions behind InfoCards and their role in an Identity Metasystem
We announced quite a bit at the RSA conference yesterday and I’ll be posting a summary of the key announcements later today.