I attended TechED USA this year. One of the key technologies that has a lot of buzz in the ITPro space is about Powershell. I attended a few sessions on Powershell and the Exchange Management Shell (Powershell for managing Exchange 2007). I found a free Powershell book online.
http://blogs.technet.com/mfugatt/archive/2007/06/11/free-windows-powershell-book.aspx
Other Powershell information.
Quest Software has free AD powershell stuff
AD templates for controlling the powershell execution policy.
www.microsoft.com/downloads/
Search for Powershell
Search for Powershell
My favorite Powershell community site
Pondering Thought 