Well, those clever chaps at xtravirt.com appear to have managed to do the unthinkable/unworkable. Getting ESX server running in a VM on VMware Workstation. They have released a whitepaper to tell you how its all done. Personally, I prefer to RDP/Citrix into my equipment remotely. But you can see the advantage of this for the purposes of product development. You definitely need a modern PC/Laptop for this work acceptably.