Hey, Hawk, just out of curiosity, what VMWare product and version are you on?
BTW, VMing our BES was the best thing I could have done. There has been zero impact on performance and response times, snapshots beat any backups out there, and now it is one less box we have powered on and wasting electricity. I am actually converting all 5 of our physical servers to one big one this weekend, and hopefully dropping our power bill.
I'm also running BES 4.16 on VMware ESX3.5, Guest OS Windows Server 2003 Enterprise w/2GB of memory reserved.
Haven't upgraded to vSphere or BES 5 yet.