Thanks for all the responses.
We have a lowish-grade HP Server with a Xeon and 32GB running Windows Server 2012 Std. It's a guest in an ESXi 5.5 host.
My understanding of Windows and Hyper-V was that you had to install Windows Server 2012 as the host OS. Then, you could host two guest VM's off that platform. In that scenario, the Server is not a VM, of course.