Part 4 of 5 - With Keith Kabza and Blain Barton - Discussing Exchange 2010 and OCS 2007 R2 PIC Federation and the new XMPP Gateway - It IS Everybody's Business!
Here's Part 4 of 5, Keith does a great job of explaining how Office Communicator, MSN, Yahoo, Gmail, and AOL unified communications can all share presence within the applications using Federation.
Check it out - https://dpeeast.hosted.panopto.com/CourseCast/Viewer/Default.aspx?id=7e831249-5477-4be4-a3cb-a819aa713145