1. They're just focusing on coding, whereas we're covering the whole landscape: Design and Development (and some Business topics to help people launch startups). We've launched with a large library of topics (HTML, CSS, CSS3, HTML5, iOS 4, Design Foundations, Introduction to Programming, and more), compared to their single topic (JavaScript).

2. They're crowd-sourcing their courses. We've hired full-time Expert Teachers who are carefully crafting courses and editorializing content so Treehouse Members know what order they should learn things in.

3. we're already profitable because we're charging for the product. I think their angle is to sell access to their users for people looking to hire, but I'm not sure.

Has any progress been made with Codecademy? I still only see three JavaScript courses. Has no one contributed to the lessons?

I contributed a lesson to Codecademy that just went live today on the DOM and jQuery: http://www.codecademy.com/courses/jquery-and-the-dom