I was digging into some aspects of Exchange 2007 yesterday for Chapter 12 of my book (Chapter 11 is finished and will be on MEAP soon) and needed to restart some of the VMs I was using. I remembered the restart-computer that comes with V2. It saved some time compared to logging into the offending machine and then going through the restart procedure.
Restart-Computer -ComputerName target -Force
Force takes care of the situation where users are logged on. It can also be run as a job.
Stop-Computer is a bit more permanent 🙂