The purpose of this project is to help developers work with data from Team Foundation Server on multiple types of devices (such as smartphones and tablets) and operating systems. OData provides a great solution for this goal, since the existing Team Foundation Server 2010 object model only works for applications developed on the Windows platform. The TFS 2010 application tier also exposes a number of web services, but these aren't supported interfaces and interaction with these web services directly may have unintended side effects. OData, on the other hand, is accessible from any device and app stack which supports HTTP requests. As such, this OData service interacts with the client object model in the SDK (it doesn't manipulate any web services directly).
In this video, Brian Keller demonstrates the beta of the new OData Service for TFS 2010.
Download The Beta: OData Service for Team Foundation Server 2010