Andrew, can you post the configuration and repro steps with which you were successful in getting the Windows Phone Emulator to launch? Also, how do you define success?
On my machine I get the emulator screen with the message "Windows Phone Emulator is doing a complete OS boot..." for 20-40 minutes followed by a BSOD (DRIVER_IRQL_NOT_LESS_OR_EQUAL)
My host machine is a 2.66GHz dual-processor dual-core Mac Pro with 6GB RAM.
The VM is running Windows 7 RTM, with 2 processors and 3 GB RAM. Parallels and Parallels Tools 6.0.11826. Windows Phone Emulator x64 version 10.0.30319.
I launch the Windows Phone Emulator from the Start Menu.
Thanks for your help! I'm sure if we compare setups I can figure out what I need to do to get this whole thing to work!