Of course, it’s not been all about the browser, either as Node.js has made abundantly clear. One of the most effective desktop applications for cartographic design, TileMill, is built with Node, among other tools.
As for the JS.geo event itself, I am intrigued by its small, focused nature. It doesn’t seem to be as informal as an unconference but may be easier to digest than the typical geo event. It will also be great to catch up with the Front Range crowd.