There has been a lot of discussions recently about the definition of HD for the web. In a lot of cases it depends on the target audience. 720p (1280×720) satisfies most users needs, especially given the current average screen resolutions, but for certain high-end users (HDMI to TV), 1080p (1920×1080) might be a valid option.
Since most of these discussions were theoretical at this point, it’s good to see that CBS put their foot down and is starting to offer 1080p for their HD episodes. No dynamic streaming yet, but impressive for sure.