Seems like you've been sleeping. Both Intel and AMD have implemented hardware support for virtualization in their current processors. VMware's ESX has been a viable production platform for server virtualization for years (since version 2.5). I won't purchase server software unless it is supported on a VMware ESX platform.

About licensing, a single Microsoft Windows Server 2003 R2 Enterprise license (/troll on/ yeah I know - the brits still spell it wrong - get with the times.../troll off/) is valid on up to 4 separate VMs on a single physical server.

Virtualization won't really be viable until part of the hardware. IBM did it in the 1960's, seems to me Intel and AMD should be able to do it by now.

I use VMware on my desktop, very nice solution for using application suites that don't like playing with other software, just fire up another virtual machine.