The currently available download requires Windows Server 2008 R2 with
the Hyper-V role to run.

You can download the vhd  and use WINIMAGE to convert the vhd and use whatever
virtualization client you wish.

I use WINIMAGE to convert the vhd to .vmdk so that I can use VirtualBox on my
Windows 7 laptop.

It's very simple (and free) to use.

Though in that case you will need to make sure of a couple things:

1) The virtualization software you use supports x64 guests (Virtual PC
and Virtual Server do not, Hyper-V, VMWare, VirtualBox do)

2) You edit the network settings inside the VM to fix the IP addressing.
As shipped it's setup to use 192.168.150.1 as a static IP, but unless
you do a Hyper-V import that setting is going to be hidden along with
the network adapter and there are a series of workarounds necessary to
fix.