I have never run MacOS on a Windows machine using a virtual machine because doing so is ethically ambiguous and in breach of software licensing terms.
In particular, I have never run Mountain Lion using VMWare on a Windows 7 host system and then installed Scrivener for Mac v2.4 on it (despite the fact that I have owned a Mac license for Scrivener for a lot longer than I’ve had access to a Mac… go figure!).
As such I have no idea that Scrivener will work fine, within the constraints of the operating system itself. That is to say, I am unaware that MacOS is designed to work on a very limited set of hardware and therefore certain parts of your system may simply not work. Webcams, CD drives spring to mind here (pure speculation, you understand) and I can imagine in such circumstances that audio might be patchy too.
Another thing that might happen (one imagines) is that you can have problems opening application windows from time to time such that they appear at the wrong size and even opacity. Again, that would be an OS compatibility thing. Within that constraint you’d find that Scrivener itself (v2.4, say) would work as expected.
One thing that I do have verifiable experience of is the other way round: using Scrivener for Windows on a Mac, by running a Windows 7 virtual machine in Parallels. I found Parallels to be quite poor in it’s implementation, and not like using a native machine AT ALL.
My suggestion: stick with Scrivener for Windows. It’s an excellent piece of software which does far more than you need it to, is incredibly robust, and avoids all of the additional steps, delays, problems and legal wranglings that a hackingtosh (or VM) would require.