The download is available at http://www.microsoft.com/downloads/details.aspx?FamilyID=00803636-1d16-4df1-8a3d-ef1ad4f4bbab&displaylang=en . Brian recently wrote a post about the new features: http://blogs.msdn.com/bharry/archive/2008/07/08/july-08-tfs-power-tool-preview.aspx
