That doesn't mean there isn't huge room for improvement in this arena. An approach like this (or OSX's versions) doesn't allow you to do anything like 'git diff' to see what's changed from version to version. I can imagine this is a very difficult problem for binary data, however. Also, distributed version control on media production software could allow for multiple users to be editing a project simultaneously.
Unfortunately, I don't really see GitHub being able to help much here. For example, any work done to make ProTools files git-friendly wouldn't also work on Photoshop files. I'd love to be wrong about this, but I suspect seeing version control in media production software would require redesigning the application's file format from the ground up, and would be a task for each software company to do on their own.