I haven't used the scenario before, but if you get a product called "Symantec Backup Exec System Recovery 2010" on educational licenses, you can :
a) Install BESR either individually on every Virtual Server OR
Install a BESR Management Server (Free) on another server with not alot of roles already on it, and then :
b) Install BESR 2010 agents to your Virtual servers which will allow you to backup your virtual environments as physical servers onto a network share, external usb / rdx drive or your iomega drive.
BESR 2010, have the functionality of converting backup images to Hyper-V, Vmware, XEN, so you can convert your backup sets to a vhd file if need be later.
http://www.symantec.com/business/backup-exec-system-recovery-server-editionBESR can encrypt your backups too, you can transfer or backup directly to a offsite location ftp etc.
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http://social.technet.microsoft.com/Forums/en-US/winserverhyperv/thread/887af44e-76dd-400a-9eec-e9229c015f8e
A similar question at the above link.
With the above question too, a person takes a snaspshot via VSS (Volume Shadow) and then rsync, having BESR backing up either once a day or incrementals means more protection and a industry standard based solution.
It gives you the flexibility to convert a besr backup image into a vhd on any machine and then use it in your Hyper-V environment.
If you have Exchange, it also gives you Granular Mailbox Restores too, you would have to have Outlook 2007 or 2010 (X86 or X64) on a 64Bit windows machine and you can then browse your backup image to do granular restores - very useful.
Hope that Helps
