During an interview with Gamespot, company CEO Todd Hollenshead gave a status update on the project and explained how the new game will fit in with the rest of the series.
"We're in - it's not pre-production, but we're still early on in that. The team is relatively new. We're still actually hiring people for the team as well, so it's not completely built out. But we really just started on that last year. It's very much deep in development," Hollenshead said. "But everything I've seen on it is classic Doom, so I don't really have worries that people aren't going to like it and start talking about it.
"It's not a sequel to Doom 3, but it's not a reboot either. Doom 3 was sort of a reboot. It's a little bit different than those, and if I told you why, I would get my ass kicked when I got back. So I'll just have to leave it at that."
Doom 4 is in development for PS3, Xbox 360 and PC, with an official release date yet to be confirmed.