A bunch of Doom 4,screenshots have supposedly leaked onto the internets. The images come by way of AllGamesBeta, who pulled them down from 4chan, and they show off some character models and environments supposedly for the upcoming shooter. There are 170 images in total, showing off many aspects of Doom 4.
The original release of images was accompanied by the news that Doom 4 was canceled, but developer Bethesda shot down that rumor. I checked with Bethesda, and I'm waiting to hear back with their official word.
We've been hearing about the development of Doom 4 since 2008. That's a loooong time in the gaming world, so it makes sense that a lot of material would be produced that may or may not end up in a finished Doom 4 game. We've even heard that the next Doom game won't be called "Doom 4" anyway.