Is it just me or does the site look optimized for Microsofts Metro interface? I brought the site up in my tablet's (ASUS Transformer) and it looked good there, too. I would say it's almost optimized for mobile devices with the exception being there are a lot of links that are tiny text and are easy to fat-finger in any phone or tablet.
It's definitely a nice example of responsive design. If you resize your browser window, you can see how the content resizes nicely to fit almost any screen