I'm really interested in John's switch because, as far as I know, at Mozilla he was working on JavaScript evangelism and performance, but at Khan Academy he'll actually be building software which I think is a pretty large change.
This is great news. After watching Salman Khan's speech at TED I got really excited about what he's trying to do for education. I really wish more public schools would shift their focus from in-class lectures to working with students in a more personal way.<p>I certainly hope the site gets more contributors from other disciplines, the majority of their content is still mathematics. Anyhow... I'm excited to see where they take this in the future.
I think its interesting how he notes that a lot of server-side devs can't make it as client-side devs. This seems like a big change from 15 years ago when UI development was considered easy and server side dev was considered more difficult.