TFS Migration Toolkit Preview
We've posted a preview of the migration toolkit over on Codeplex, and the PM for the product blogs about it on his blog.
So what does it let you do? You can use it to import data from other systems (bug tracking systems, version control systems, etc.) or to synchronize with other systems (project and portfolio management servers, helpdesk software, etc.). It's tailored for writing applications that move data into team system. Of course, the Visual Studio SDK is also available.