All of the methods he uses have been known to the web-app security community for a while. He's simply raising awareness of what's already broken.
Keeping these things quiet helps nobody. We need more privacy and security issues to be publicly demonstrated so that they'll get fixed instead of ignored.
As an example, his work exploiting wireless routers to get location is genius. Who would have thought that having your router's wireless MAC available to your internal network allows a website to determine your location to within a few hundred feet? It uses well known and oft ignored attack methods to produce a sensational result with which everyone can immediately identify.