Eric Sloof from NTPro.nl gave a very good presentation at the Dutch VMUG 2008 event:
Managing VI3 with Powershell.
This presentation focuses on the tools that are currently available for PowerShell. It also gives you an insight on the VMware PowerShell extensions and presents a short introduction to PowerShell as a scripting language.
Eric already posted his presentation on his blog, but here is the video Johan recorded: