I think that virtual machines are one of the coolest products from the last decade. And what I like about them is the ease of which you can do purely hardware-related management using plain scripts. No need to go three floors down into the datacenter to manually wire up a new cluster. All you need to do is to use a script that will create the entire cluster from scratch!
In five years probably, virtual machines will be a must-have tool for the regular IT administrator. Not only for ease of management, but only to consolidate all your servers in a few very fast machines. I am not sure what would be the CPU speeds the bus speed and the memory by then, but it would be certainly affordable to run a few virtual machines - one with your Exchange box, another one with the payroll database, and so on.
And, from a management perspective, Virtual Server really shines. There is a nice web page right here with all sorts of nifty scripts to manage your servers: add disks, add controllers, etc.
Here is a really simple script to add a new harddrive:
Set objVS = CreateObject("VirtualServer.Application")errReturn = objVS.CreateFixedVirtualHardDisk _ ("C:\Virtual Machines\Disks\Fixed_HardDisk.vhd", 20)