I tried to install Windows 8 Developer Preview on my Lenovo W520 laptop as a VHD boot. All seemed to go well following the same process as for windows 7. I got a nice new blue Window 8 boot partition choice screen (which went back to the Windows 7 DOS like one after I made Windows 7 my default partition).
If I selected Windows 8 it tried to but but ended up with the error
‘Windows could not complete the installation. To install windows on this computer restart the installation’
No more info than that, I suspect it does not like VHD boot. But I don’t have time to dig now, more later I am sure……