I think there is some confusion going around about the various forms that HyperV can take. There are a number of different ways to use it, but the easiest for you will be to simply enable the HyperV role within Server 2008 R2. Don't worry about doing anything else.
Set up the r2 server on the physical box, and enable the HyperV role on it. Just don't install anything else on the physical box.
As for your licensing, hopefully this will clarify:
Hopefully this will help clarify:
Server 2008 R2 license 1:
1. Install on the physical hardware using the Physical install key.
2. Install in the first HyperV child you run up using the Virtual install key.
Under Microsoft's EULA, you can use the same license for both the physical box and the first VM as long as all the physical box is doing is running the Hyper-V management console. If you want it to do more than run HyperV, then you'll need to purchase a separate license for the physical install.
If you want to run up additional servers after the first, you'll need to purchase additional licenses. If you purchase Server 2008 R2 standard, you'll need one license per VM. If you purchase Server 2008 R2 enterprise, then as stated above, you can run up to 4 VMs.
Mark, by HyperV guest license, I assume Cmosk is talking about the Virtual installation license as opposed to the Physical installation license.
On a side note, be careful running a TS on a virtual system. Make sure you've got appropriate hardware to support it. In my experience, disk I/O can bottleneck really badly on a virtual TS if you're not careful.