I found this interesting....not surprising...but interesting. Mostly that he'd even toss that stuff out.

There will be a Doom 4, we don’t have it scheduled or a team assigned to it, but there will be a Doom 4. There’s going to be a Quake Arena sequel. There’s a Wolfenstein thing in production. We’re following along with all those. This game doesn’t have to be Doom. It’s going to be something different.