tangential, but I always wished that somebody with more time and knowledge than me would have created a slim bootable linux hypervisor that could then boot Windows, in which you could then run a linux that "knew about/shared memory with" the hypervisor. Think of the goal as being, I can reboot the linux or I can reboot the Windows (or other OSes) without rebooting everything.

I would have liked it better if VMware worked that way, or virtualbox now.