Recently I came across Milissa Tarquini's article in Boxes and Arrows that addresses (and dismisses) the concept of the page fold for screen design.
I found it a thorough (and compelling) argument about how arbitrary the "fold" concept is, and how there is adequate research out there to support designing for much longer pages (yay!)
Her conclusion: "Stop worrying about the fold. Don't throw your best practices out the window, but stop cramming stuff above a certain pixel point. You're not helping anyone. Open up your designs and give your users some visual breathing room. If your content is compelling enough your users will read it to the end."