This page contains links to UCMA 2.0 Core info and tutorials related to the presence feature.
An overview of the presence feature:
http://blogs.msdn.com/kobyl/archive/2008/11/16/presenting-presence.aspx
Containers and Categories:
http://blogs.msdn.com/kobyl/archive/2008/12/09/buckets-of-pieces-of-presence.aspx
Working with the static XSDs:
http://blogs.msdn.com/kobyl/archive/2009/03/12/serializing-and-deserializing-the-presence-xsds.aspx
http://blogs.msdn.com/kobyl/archive/2009/03/12/xsd-c-class-published-presence.aspx