Alexey Kouzmitch has done everyone migrating to Beta 3 Refresh a favor by creating and sharing a tool that will expedite the uploading of report templates, which is the most cumbersome step of the migration procedure. Thanks, dude!
Anyone who's read the document realizes that the final step is a rather long manual process. Well, no more. I wrote up a quick utility to upload Report templates from a Process Template up to your TFS Report Server. It updates DataSource references and even sets the default value for the Project parameter.