Author here. That may be the point of media queries, but they don't (in my limited understanding) achieve that very well at this point in time. The article I linked is explicitly saying "here's a rule which will allow you to load your mobile stylesheet that works with current mobile browsers." Of course, media queries for iPhone 4 deal with different kinds of pixels, so you can't rely on the standard, you have to dig into device differences.

My goal was a simple enough solution that is suitable to use places like blogs or Hacker News. If you're trying to build a very slick eye-candy-heavy site, then media queries might be the answer, but they require more testing and thought than my solution.