Here's some more detail as requested by @ClayM and others...
The Year of Rock is the work of two guys, myself and @bsstoner. It's powered by the @getinstinct platform, which we also built.
Starting next week, we'll send a weekly guitar lesson by email to everyone who signs up. The lessons are entirely interactive. They listen as you play and give you feedback on each note, using pitch detection software we designed. You can demo some lessons we've already made at http://getinstinct.com
There's no human teacher, it's entirely automated and works in the web browser. The entire site is built in JS and HTML5 (including node.js on the backend), except for some Flash for the audio processing (unavoidable given the current state of browsers).
One thing that's cool about the Year of Rock is that the course is partially crowdsourced. After we create the intro lesson each week (such how to play a blues scale), our users can add practice music and riffs via our tab editor. There's a voting mechanism similar to HN or reddit to help the most popular submissions bubble to the top.
From a usability perspective, we've learned that the course needs to be more flexible than Code Year. Almost everyone will skip weeks or start late. Some people will enter the course with more experience than others. So the course can't be too linear. It should be okay for people to approach it like a buffet.
There's still plenty of time to adjust things, so would love to hear any questions/ideas/comments...