I started an entry last night on my roll out of server virtualization, but instead of posting it, I'm issuing a bit of a warning. There are issues using Windows 2003 Server x64 as a VMWare Workstation host. Idle 32 bit VMs use a significant amount of CPU time.
I started a thread on the problem on VMWare's support forums.
I'm still bullish on server virtualization, although we've yet to reach the full potential on the x86 platform. But it should be an interesting year for the technology.