This new version of the video does not yet work but appears to be based on HTML5. The css files reference HTML5 and have a number of "webkit" specific calls. Webkit is the browser engine used in the iPad's mobile safari. While the videos don't currently play, the "fullscreen mode" reportedly already works in the iPad simulator.
The iPad, like the iPhone and iPod touch, doesn't support the Flash plugin that CBS.com uses for computer-based browsers. More and more sites, including YouTube are testing HTML5 as an alternative, however, so It will be interesting to see if CBS.com pulls the trigger on it, and how many other big media properties follow suit. Hulu anyone?