I don’t think so, and here’s why. The EULA that this post refers to says (emphasis mine) “You may not use the software installed on the licensed device within a virtual (or otherwise emulated) hardware system.” I’m certainly not a lawyer, but it sounds like the scenario addressed is taking the copy of Vista that you’ve installed on your PC, and running that same copy under virtualization.
The EULA (yes, it’s titled Ultimate, but it includes terms for other editions) defines a licensed device:
Before you use the software under a license, you must assign that license to one device (physical hardware system). That device is the “licensed device.” A hardware partition or blade is considered to be a separate device.
And the prohibition against using Microsoft’s DRM within the virtual machine makes no sense unless you are talking about two identical copies (same activation key) of Vista running on top of each other.
So there’s some ambiguity here, and it would be great to get some clarity from the Vista team. But here’s the thought I keep coming back to: if you go out and buy a copy of Vista that you intend to run only under Parallels, the only thing that seems to remotely qualify as the licensed device is the virtual machine itself. Here’s how I think the legalese translates:
“You may not use the software installed on the licensed device within a virtual (or otherwise emulated) hardware system.”: You can’t take the copy of Vista you installed on your PC and run it under any kind of virtual or emulated system.
“You may use the software installed on the licensed device within a virtual (or otherwise emulated) hardware system on the licensed device.”: You can take the copy of Vista you installed on your PC and run it under virtualization or emulation, but only on the same PC.