UPDATE 01/29/2013:

• I'm no longer using Windows service and srvany, I recommend to use standard Windows Tasks Scheduler.
• Now you can restart the script anytime and it will do all needed cleanup work - will shut down the VM, clean up the environment, etc. So basically, you just stop and start the task in Windows Task Scheduler and that's it.
• There was a bug, when you build more then one image a day, it won't be able to save a backup copy and fail. Resolved by adding date/time part to the backup file name

This is a script that works with Hyper-V and MDT and automatically builds WIM images for you. It uses MDT 2010 with fully unattended Task Sequences and saves captured WIM file to any location, which can be SCCM OSD source of OS image. Now your image build process becomes "set it and forget it" solution, and if you enable Windows Update steps in the standard Task Sequence, you will be getting all latest patches from Microsoft when you build your reference images.