If you haven’t already checked it out, I wrote and published a PowerShell module on CodePlex a little over a year ago. It’s called PowerEvents for Windows PowerShell, and allows you to easily work with permanent WMI (Windows Management Instrumentation) event subscriptions. Some folks may not be aware that I’ve also written comprehensive documentation on the theory behind WMI events and why they’re useful. This ~30-page PDF document is included in the PowerEvents download, and is useful even if you do not want to use the PowerEvents module.
As a bonus, the PowerEvents module was mentioned just recently in the PowerScripting Podcast (listen around 1h19m)!!
Listen to my interview with the PowerScripting Podcast back in December 2010!
PowerEvents Download Link: http://powerevents.codeplex.com/