In order to use the cmdlet first you'll have to grab the Microsoft Visualization Components from Microsoft Research. If you don't want all the visualization components here is a zip file of just the treemap generator dll.  Unzip it and put TreemapGenerator.DLL in your scripts folder. Grab this file to get the scripts I demoed at the meeting. Let me know if you have any questions or comments. I'm hoping to do a full writeup for the blog soon.