My Google Summer of Code project at WordPress, Code Revisions, finally is available in the WordPress.org plugin repository. It is not final yet, but close to. The whole development process was and still is accompanied by weekly posts on make/core. Features and bugs are kept track of on the WordPress gsoc trac. If you find a bug don’t hesitate to report it there.
Go get it: http://wordpress.org/plugins/code-revisions/