Fellow id man John Carmack revealed that Tech 5's continued progress has really helped with the games development, which is already being approached tightly. What, DOOM 3 wasn't?
"When we show it to you you’re gonna love it," said Hollenshead, before passing the floor over to Carmack. All the development tools and technology needed for DOOM 4 are there, so it's all about the content and really painting those corridors red.
Source: VG247