A set of screenshots, supposedly renderings from DOOM 4, popped up on All Game Beta today, supposedly coming from a source claiming that the game has been cancelled. Bethesda has since denied the rumor, telling Joystiq bluntly; "DOOM 4 isn't cancelled." No one from Bethesda has commented on the validity of the screenshots.
DOOM 4, a game rarely referred to outside of rumors, has been tagged as cancelled before: Last October rumors were claiming that the game had been put on indefinite hold. Bethesda denied those rumors as well.