Regarding the Visual Studio 2010 and .NET Framework 4 training courses. The virtual machines for those courses are running Windows Server 2008 which does not support native boot to VHD. For someone like me, who is using a laptop that does not have intel virtualization technology compatible processor, is stuck using Windows Virtual PC 2007. And it's a pain in the asss to do the lab in such a configuration.
Have you considered upgrade the os to Windows Server 2008 R2 to support native booted vhd?