I posted the following on Powershell team's blog -

Powershell V1 does not give a cmdlet to support WMI events, I have written a simple powershell script to help users who want to write monitoring with powershell  for V1(Please see attached.) (A brief intro of WMI events at the end of the post for the uninitiated) ...

http://blogs.msdn.com/powershell/archive/2007/07/16/working-with-wmi-events-2.aspx