In case anyone else was as confused as me ....

There is the TwentyTen theme for WordPress, which has nothing to do with this.
There is the TwentyTen Sass/jQuery plugin which this is based on.
There is the TwentyTen WordPress plugin, which is what was reviewed above.

Naming nightmare :/

It's a nice WordPress plugin though. Now I need to find an excuse/reason to install it :)