While Doom 4 was a no-show at Quakecon this year, the game is apparently still in development. The decision to announce the game back in 2007 was said to be an effort to attract new talent to the studio. We do know that as of 2011 the game was being retooled, yet the game is apparently still in development.
Of course, there is no news on when the game might be released or when we can expect an update. In the end, as it always is with id Software titles, it will ship when it is done, whenever that might be.