Seeing as you build your own 'filesystem' on top of a simple key/value interface, I think advancing the backend support might be good 'low hanging fruit'.

It doesn't even have to be something as 'cloudy' as rackspace, support for something like webdav as an ARQ backend would also be nice.

That being said, I have actually no idea about the codebase and user base, so this could be a completely wrong assumption :)

Personally, my biggest 'problem' with Arq at the moment is, that the iPhone client works, but I'm missing stupid small things like thumbnail previews for uploaded images.

Would love to see it - for cloud files - and all swift deployments (the whole cloud files source is open sourced as part of openstack). let us know if we can help in any way.