For example: a (para)-VM that's capable of running off Linux filesystem or subvolume (so you don't need to allocate separate partition or disk image for that),

For example: a (para)-VM that's capable of running off Linux filesystem or subvolume (so you don't need to allocate separate partition or disk image for that), capable of running all the win32 binaries, and seamlessly integrating into Linux desktop and infrastructure (i.e. non AD-Kerberos would be great).