We're mostly looking at supporting remote volume sync in docker itself, with a pluggable transport - could be smb, nfs, periodic rsync, sftp... bradfitz started an awesome contribution with a full remote-fuse-protocol sync :) pretty awesome but we haven't been able to merge it yet because the volume system needs to be made sufficiently clean and modular first.

The advantage of doing it in Docker proper is that it works in all distros without outside dependencies, instead of just boot2docker.

Note: we are looking for help on this, if you feel willing and able. Even better if you can invest some recurring time to maintain and help others contribute.