One of those ideas that, after you hear it, you think ya, that makes total sense, why isn't this already being done? Very cool project idea to be working on still in high school.
Who says it isn't already being done? I'm pretty damn sure Google and Bing do some sort of topic modeling (LDA, LSA or something else) that basically does the same thing - though the exact method is not the same.
Watching the TED talk, he seemed to be comparing his search results to that of some academic search engine, which are generally very dumb and purely keyword based. Google does a whole lot more than that. Kudos to the guy for figuring this all out on his own, but I don't think this research is as original as portrayed by the media here.
It's not novel work. It's an toy implementation of standard technology. It's impressive for a young person to understand and synthesize the components, but it's an engineering practice project, not an innovation.
http://www.youtube.com/watch?v=fmxNuVDJZEY