Carmack 'not permitted' to discuss Doom 4

Id Software co-founder John Carmack asked an internal management team whether he could discuss Doom 4 at this year's QuakeCon event, but was told to avoid the subject.
Speaking during a Q&A session which followed his QuakeCon keynote, Carmack was asked by a fan to discuss the progress of the next-generation Doom title.
"I can't," Carmack replied, "I actually asked about whether I could say anything related to the development, and the answer was, no, I couldn't."

http://www.computerandvideogames.com...iscuss-doom-4/