I've put together a simple application to publish build status information from Team Foundation Server to Twitter. It's built as a windows service that listens for the various build status events from TFS and tweets information depending on the event it receives. At its core it uses the Readify.Useful.TeamFoundation.Common assembly from TFSDeployer for listening to the TFS events and the TwitterN library from amptools for talking to Twitter.
At the moment the application is still very much an alpha with things like error handling and customisation of messages not done as yet. Even so, here's what some working results on Twitter:
If you're interested in getting a copy for yourself let then me know and I'll put the project up on codeplex.