Team System Product Team has released a new virtual machine with latest updates for TFS as well as for Power Tools.
In addition, the operating system and programs installed were patched with all updates as of December 8, 2010. This virtual machine will stop working on June 1, 2011, when the trial software expires. A new version of this virtual machine will be made available before this one expires.
The Virtual machine could be used under Hyper-V on Windows 2008, and 2008 R2, Microsoft Virtual PC 2007 on Windows Vista, and Windows Virtual PC for Windows 7.
Enjoy it :)