The New York Times broke the news, and now Wizards of the Coast has their announcement up. Fifth edition D&D is currently in development. You can sign up to be notified when the playtest starts through a link on the Wizards announcement page. I put my name in the hat, so we'll see if I get the chance to participate.
I doubt that they will be able to accomplish their goal of reuniting the D&D community, but I am anxious to see exactly what direction they take. Most likely, they will move things back toward 3E, with options for a more rules-light version to appeal to the people that prefer that approach. At the very least, hopefully they will open things up for third-party development again. I am somewhat heartened to know that Monte Cook and Mike Mearls are driving a lot of the new edition, as they are both designers that have produced some of my personal favorites over the years.
Regardless of what happens, it's going to be interesting to watch.