Why would Google spend time doing this, Tux? There are far too many competing services to justify this. Plus, if you are syncing from a dropbox account, wouldn't the data ALREADY be on your computer (or one you have access to)? Just point Google drive to that folder and your data is synced.
Show me another service that does a direct import of IMAP data from another service. The only way I've ever found to sync IMAP profiles is using a client and draggin/dropping between the two, or some clunky scripts that does it (imapsync).
But something tells me you already know this all of this, didn't you?