You will see that the VHD licence is no longer royalty-free, from now on it will be OSP (Open Specification Promise), "an irrevocable promise from Microsoft to every individual and organization in the world to make use of this patented technology for free, now and forever when implementing specified open standards". 

For the full details you will need to read PressPass and the Windows Division Blog, or jump straight to the <this link is broken at present but I will update it when it's back - sorry Clive!> page.