Learn a little programming and earn badges
Learning to program can be very frustrating, especially if you are not attentive to detail. If you miss a point of syntax and leave out a period you can easily get lost. The tutorial does not (yet) have a good way to give adequate feedback on errors, but it does provide hints. A non-programmer could easily get stuck at a number of points.
One exercise I particularly liked was having the user debug a few lines of code. As you complete lessons you earn badges, and your badge count appears at the top of the page. So besides being a nice little tutorial, Codeacademy is a decent example of gamification! All in all, I love the concept and believe they have done a nice job. If you get REALLY good at coding, you might end up like this:
ProfHacker reviewed the site and had pretty much the same reaction. They also mentioned a tutorial called Hackety Hack (Ruby on Rails) and the W3Schools “Try It Yourself” editor. If you think you might be good at writing this kind of tutorial, Codeacademy has a Teacher Beta program that is looking for folks to write for/with them.
Disambiguation: Codeacademy is not Code Academy, a Chicago-based training company. It is not an online university, and do you not get any kind of recognized credit for completing the “courses.”