Anyone experimenting with Windows 7 Differencing?

[MadMonkey]

With Windows 7 supporting Native Boot of VHD, an interesting new option for Hard Disk Protection is now built into the OS itself: differencing. Differencing Disks function like a sandbox on a partition level, a concept familiar from Returnil, Deep Freeze and all the "Shadow" apps. Unfortunately, there are a number of usability issues, chief among them that there is no ready interface and everything has to be done manually. For now.

I'm curious. Has anyone been experimenting with it, yet?