"...they are using the DOOM3 technology now which is finished"

This was a simple mistake by Rich that just snowballed a little... So since it seems that this was picked up elsewhere as factual we've got an official statement from 3DRealms to clear things up. Here ya go:

"I guess I need to clear up some confusion. We are not using the Doom 3 engine for Duke Nukem Forever.

That said, I'd also like to take a moment to point out something about the gaming press. Very few people ever even try to contact you for fact checking, like Gamespot did. When they ran the story about the engine change, they ended it with "Attempts to contact 3D Realms for comment were unsuccessful as of press time." The news story was posted 35 minutes after I received an e-mail from them requesting confirmation.

Gamespot, I apologize. Your e-mail came in at 10:04pm and I was working elsewhere in the building. I will try to be more accessible to you in the future."

There you go. George actually confirmed here on Shacknews at the end of May that 3DRealms has their own 100% from scratch rendering engine. Also, here's an mp3 of the call if you're really curious.