Is it possible to have a machine that is a Hyper-V server, be able to directly boot from cold start into the VM from the native hardware the machine runs on?
A non-virutalized server is available in addition to the described Hyper-V host.
All machines are running Windows Server 2008 R2 x64. The VM is Windows 7 Enterprise x64.
You can set it up so that the physical machine has two entries in its boot configuration database, the one for Hyper-V and the one for the VHD containing the VM image. You'll be presented with a choice when the machine boots, one for Hyper-V and one for the VHD. Getting both sets of drivers installed in your VHD is possible, though a little annoying to navigate.
See "bcdedit /set device" and "bcdedit /set osdevice" for information about booting directly from a VHD.
So, yes, in contrast to what "icky3000" said, you can do what you want.
A Hyper-V server itself can't boot into a VM because it must run the hypervisor layer and the only OS you will see on that box is the parent partition. It is, however, possible for a physical server to boot into a VM/VHD if you're running either Windows 7 or Windows 2008 R2. For more information on how that works, look here.