Thank you SO MUCH for that Hackereducation link, Elizabeth! I read all the comments and considered them. There are many more "hackers" than there are "masters" in coding, and "masters" I believe have at some point taken a structured coding course, and apply that learning
Structured: My knowledge of PASCAL and BASIC (totally dusty now) were obtained in college courses in the early '80s. I actually ended up teaching BASIC course to middle schoolers in 1986 on TI99/a computers, which was a blend of the two languages - I called it "Modular Basic".
Hacker: My knowledge of PHP/MySQL is all gained from "hacking" in order to make websites, and it seriously limits me when doing development. I can take a PHP script and change variables and tweak it around pretty well, but I can't start writing something from scratch without looking at models.
As educators, I think we should champion the "structured" learning path - but maybe we need to lead with some "hacking" just to get students over the hump of how hard it is to "make cool things" from scratch.
I have a student who has a "hacker" knowledge of DM (it's a scripting language used for a multiplayer game ecosystem he loves). He changes the hairstyles of his avatars and such now. EVENTUALLY he might get good at it...but not in the next few years. He is not part of a development team with tight deadlines and deliverables and isn't being fed successively more difficult projects.
I'm hoping CodeAcademy has worked out some of those bugs mentioned in the comments, but I think that doing this together (me plus the students) I can compensate for its difficulties, without having to "be one page ahead of the students" with the actual lessons. But there are only 19 lessons there, so at some point we'll move over to http://w3schools.com/js (We've already used w3schools for HTML/CSS.)