"Version 3 of the Google Documents List API has been officially deprecated as of September 14, 2012", as has been announced here:
Will there be a migration to the Google Drive API? In my opinion, user security would benefit big time from this change: currently, "Backup" requests a large scope of user rights, and especially https://docs.google.com/feeds/ implies "View and manage any of your documents and files in Google Drive". I do not like the idea that a mis-configured (or maliciously manipulated) application can purge my Google Drive.
If the scope could be essentially limited to https://www.googleapis.com/auth/drive.file ("View and manage Google Drive files that you have opened or created with this app"), that would be a major step forward.
Apart from that, thanks for this gorgeous plugin.