Works just fne. I got it working last night.
I have my 17 inch MBP. I will not buy another Mac laptop until they make a 17.
I enjoy Snow Leopard. I HATE many parts of Mountain Lion and Lion. I'm only using the VM for Xcode.
I have the VM running Xcode 4.6 in ML 10.8.2 at 2560 x 1440 on the Thunderbolt display off of the SSD with 4 cores and 8 GB of RAM.
My MBP is booted to 10.6.8 and I can enjoy the OS that doesn't suck (10.6.8) and limit my exposure to ML thanks to the VMWare VM.