Tom Occhino is a software engineer at Facebook since 2009 and the video above he is presenting React.js and answering a few questions like: Why they "invent" react.js? How easy it is to use? What brings new to the game ?
All those questions might not seem important but after reading the documentation at http://facebook.github.io/react/ and listening the conference it seems awesome.
I got to admit, I'll have to play a bit with the framework to see how it works, but based on the documentation and conference, I might start a basic project just to get an idea of how easy it is to use it.