That site design is a new project from The Center for Public Integrity. They're looking at ways to improve the reading experience of long form content. In particular, they're looking at certain aspects of tablet media apps and are trying to integrate them into an HTML5 theme that will be platform independent.
Just so I'm perfectly clear: This is the next big thing for digital content. (It also goes to show that apps are last year's hot trend.)
I'm really looking forward to this. (Just for the pagination alone, I love it.) There have been any number of times that I've done a tl;dr simply because I got tired of scrolling down an exceptionally long article. At one point I started using dotEpub to save the articles as Epub so I could read them in a reading app, but I'd much rather not have to go that extra step. I don't always get back to the saved article (too much effort).
via Editor's Weblog