zir_blazer,

I'm very interested in having a system as you've described. To make sure I understand, I'll describe in my own words what I want.

* I turn on my computer and it boots to some OS ... Linux, Windows, whatever.
* An option to load a VM image from a menu screen (vhd drives or whatever) is accessible.
* I select a Windows 7 image and it loads (optionally) full screen.
* ALT-TAB'ing I can load another image of say, Linux.
* Both images are now running with complete access to the local hardware.
* The two running images are actually only writing back to their respective .vhd files.

This would make it awesome to reinstall a VM image as I make changes to it over time. With SSD and new PCIe drives coming out, writing back to a single file will be plenty fast enough.