For a Linux user, you can already build such a system yourself quite trivially by getting an FTP account, mounting it locally with curlftpfs, and then using SVN or CVS on the mounted filesystem. From Windows or Mac, this FTP account could be accessed through built-in software.
I mean, isn't that just about what happened to Docker?
They wrote a really nice wrapper around cgroups/ns/tarball hosting and then struggled to monetize it because a large portion of their users are exactly the kind of people who could set up a curlftpfs document cloud.
Sir, this is a Docker, not Dropbox