Eric Charran published his whitepaper on: Managing social networking with Microsoft Office SharePoint Server 2007.
The whitepaper points out a few ways that SharePoint can be used to expose more information about a person inside the firm. It does not provide the level of interaction or a flow information as powerful as Facebook.
SharePoint does provide a nice platform for exposing more information about the person by pulling information from multiple systems. In particular, I think the use of the techniques and tools discussed in the whitepaper can be used to exposed internal expertise.
