I think responsive design that changes when resized like this is a bit annoying and unexpected. When I'm using the page and I resize it, I lose my place on the page and all the content reflows. There's nothing in traditional media that works that way.
And that is exactly the point - it feels like we are finally waking up to what the web can really do that traditional media cannot. I'm sure in a few years having the content reflow will be something users expect of every website (not that it is something people do all the time - see the comment that guywithabike made).