I've heard plenty of requests for tools to migrate data from competitor products to TFS, and I'm trying to find out which tools have the highest demand. If you need a tool to integrate Subversion and TFS, for example, please reply to this post and let us know. Or better yet, create a new item in the issue tracker so that others can vote on the tools they want to see developed.
I'm also thinking about how to encourage the community to work together to develop migration and synchronization tools. Surely there is more than one person with a need for a SVN tool that is willing to develop it using the toolkit, so why not bring those heads together?
I'll start it off and open an issue for a SVN to TFS migration tool, and see where that goes. Hopefully others will follow.