I’ve written a lot about identity and identity management over the past year, and interestingly enough, my husband has lately gotten interested in the same subject and is doing work in that area at Microsoft – particularly as related to hybrid IT and the new private cloud model. At Microsoft, ID management is based on four pillars that organize the identity management concepts for easier understanding. This TechNet document discusses how to create an identity infrastructure within a hybrid network environment, using those four pillars.
http://gallery.technet.microsoft.com/The-Four-Pillars-of-31ee0915/view/Reviews