What is the backup technology?
Right now the answer is not pretty. Going to get better in Q3 with Exchange 2007 SP2....
Having said that, Exchange 2007 does NOT have the same requirements as Exchange 2003 in terms of restoring mailboxes to the same server. There are certain requirements that must be met but these requirements are much less now.
There are also backup issues to consider (Like backing up to usb drive). Search the archives of this list for issues you may encounter and jump on the partner newsgroup site there is a ton of info there.
For example when using snapshot backups with buex read and understand point 8 as it refers to Recovery Storage Groups here:
http://seer.entsupport.symantec.com/docs/279927.htmHTH,
M