What percentage of users is Google considering for 'above the fold' and are they just penalizing for ad content or do logos, images and header junk get penalize

What percentage of users is Google considering for 'above the fold' and are they just penalizing for ad content or do logos, images and header junk get penalized as well? For example, the WordPress TwentyEleven theme as seen in http://browsersize.googlelabs.com/ http://browsersize.googlelabs.com/ shows the first article header at the 50% threshold, buried below the generous header and image banner. Would a site based on this theme or a similar design face a penalty?