please notice the scroll bar to your right
Google has released a tool that allows you to see how your site is viewed in different browser resolutions. The tool will likely have plenty of people getting nervous about their sites. In the olden days, people didn't know what a scroll bar was, and might leave a site, not understanding that there was more content to see.
Please Scroll (thanks, @tsand) reminds us that it's NOT 1996, and that internet users understand how to use a scroll bar. Three Minds has an old (but still relevant) post on the subject as well.
While some may now have their developers cramming all of their content into the top left corner of their sites, we suggest that the best tactic is still great design, great content. Produce both and you'll engage your audience. Even below "the fold."