I like to have a few forms of backups and this is a great plugin.
I was reading other support threads asking about backing up the entire network and the response was that more members' servers are not setup to handle that sort of resource requirement. I can understand that.
But I can also understand that running the backup on each site over time is certainly sustainable. For example it could start on the lowest blog ID, and work its way up, keeping a running average of time required per backup so that the timing could be adjusted later if the script was moving too quickly for the server to manage, or if it was moving too slowly for the full backup to complete in off-hours.
Sure an entire dump or image could be performed, but this method would allow for the restoration of a single blog if needed.
I am very interested to hear if this might be a possibility in the near future.