In a feature on Doom III on Pulse (the G4Tech TV show), Todd Hollenhead confirmed that RTCW2 is in development at another studio - he didn't say what engine the game will be using but the Doom III one is most likely.
Looks like id is getting their money's worth with the engine: Quake IV and RTCW II.
Looks like id is getting their money's worth with the engine: Quake IV and RTCW II.