Implemented this a few years back by abstracting the upstream callbacks. You can mount pretty much any API endpoint as a filesystem with a bit of JavaScript glue. The FUSE layer is in Go: https://github.com/autovia/wfs
Written in ruby, difficult to install. Have a look at the install requirements.
Like all ruby apps you need a full build environment and tons of dependencies, and if by chance a specific gem fails to compile you are toast in dependency hell.
Given the goal of the project an easier to install and use stack would have helped them.
That's what I did a few weeks ago and I have begun drawing my friends over to it. Every few days I go on facebook and talk about what I've figured out about diaspora.
I've also begun posting my hobby content on diaspora first, then facebook a few days later. When I post on diaspora, I post the invitation to see it on diaspora.
Listening to Zuck's weaseling yesterday I felt vindicated.