After hours of head banging and hair tearing, we’ve discovered how to restore Exchange 2007 storage groups to a recovery storage group from a VSS backup. [Doing it from a streaming backup – eg. ntbackup is different.] From a RSG, you can merge individual mailboxes back to the live storage group.
Unfortunately this hasn’t documented by Microsoft, so it took some experimenting to get it to work. 🙂
HOWTO: Restore Exchange 2007 from Windows Server Backup
HOWTO: Restore Exchange 2007 to a RSG
HOWTO: Merge mailboxes from RSG to live SG