Slow Boot Slow Login (SBSL) Hotfix Rollup for Windows 7 and Server 2008 R2 Available Today!
Mark Morowczynski has just blogged about this enterprise hotfix rollup so I wont repeat what's already been said, but if you have Windows 7 or Server 2008 R2 then you should go apply this.
Jeff Stokes who was one of the key contributors also talks about it here:
https://blogs.technet.com/b/jeff_stokes/archive/2013/03/12/download-this-kb-now.aspx