I didn't look closely at the kickstarter page but I use gitdocs[1] which is basically works like dropbox but syncs to a git repository. It works ok for my (light) usage.

[1] https://github.com/bazaarlabs/gitdocs

[edit] It looks like git-annex solves the large binary blob problem with git (which I don't think gitdocs does) so maybe they could be integrated?