I have now confirmed beyond any doubt that the machine only freezes up when connected to an external monitor (Apple LED Display) or a projector.
It has been fine all week whilst I have been working away in Europe, and I have really put the machine through it's paces.
I arrived home, plugged in, and after opening up 2 VM's it froze straight away.
I shutdown, did the same again three times ... same results.
Booted up without an external monitor connected, and it's been fine.
The OSX 10.8.3 update started all this, and going back to previous versions of VMware does not help.
Time for more logs 