We will have a feature in this year that will allow you to take the backup "Dynamic Volume" and use with any products being NAS-R3 Enterprise or DSS.
Even if you had a Microsoft server and it burned you would have to rebuild a new server install the backup software (some are very $$ - our backup feature is free) and restore the tapes or vtl or drive. You won't be able to take the MS backup and place on a MAC system either.
You can take our backup and use any Linux system with a free backup program to do a restore if need be. So we do have some flexibility.
Also keep in mind we do offer NDMP .
You could also replicated your data to another NAS-R3 for such issues as you described with disaster recovery procedures with our Data Replication or even Volume Replication with DSS.