Over at my personal blog (www.mikepoulson.com) I have a post on using Differencing Disks with an SCVMM template. The main issue I ran into when first doing Diff disks with VMM was making sure the Parent VHD was on the target HyperV host. The PowerShell script at http://www.mikepoulson.com/2011/07/how-to-create-differencing-disk-vm-from.html does that work for you.
Check out my Home power monitoring post. http://www.mikepoulson.com/2011/07/new-home-power-monitor.html Currently uses both Microsoft-hohm and Google Power meter. I will soon have to find a new solution.