User blog comment:Rupert Giles/Prototype for a new article layout/@comment-452-20141211193256/@comment-5275700-20141211195844

I think it's pretty easy to see that the article content is the focus of the page now. Removal of the right rail is a bold choice, to be sure. But we've heard repeatedly that the rail is a dead space, either ignored or giving a feeling of clutter. The rail doesn't have too many fans. Are you one? So we're trying this out. Without the rail, the ads need to be worked into the content area, and this does present some challenges. Both technical ones, and challenges to expectations.

To quote another part of the blog, about ads:
 * It’s highly unlikely we will get this experience right on the first try