While I've certainly made use of typing random stuff into my web browser, the browser can't compete with a shell until it learns to display results as concisely.
Unix has get-results-and-get-out behavior. There's no "fluff"; some commands won't even display an error string, they just return error status. (This is pretty ideal, to me.)
If I must use a GUI, I find Apple's Spotlight closer to what I want, than a browser's location bar. For example: while I could ask Google to solve 2+2, I still have a web page wrapped around the result (that probably replaces whatever web page I was using); with Spotlight, the answer to 2+2 appears before I even hit Return, and when I hit Esc the entire query box disappears and I can resume what I was doing before. That is how a "super location bar" needs to work.
Actually, it's not the address bar per se, but the search box that's the default home page on so many browsers. For many people "Google" is the "Internet" and they type into the Google box shown by default things like "cnn.com" and the like.
I guess Jeff's point may have been aimed at the techie crowd (a Chrome screenshot with a JS example), and for this smaller demographic of web users, I can't agree more.
Feel free to reuse ad nauseam with Twitter, email, Google, Wolfram Alpha, command lines, cloud computing, crowdsourcing...