Thanks to PlanetWolfenstein for its forum post revealing
id Software's CEO Todd Hollenshead has indicated a sequel to Return To Castle Wolfenstein is being created, as his interview on G4TechTV show
Pulse included his indication that the sequel is
"currently in development by an 'outside studio'." According to the forum post:
"There was no mention of the engine it would be on, but i'm guessing the Doom 3 one will be most likely", and rumormongers are pointing to the
Splash Damage website, where the UK developer behind
Wolfenstein: Enemy Territory and contributions to
Doom 3's multi-player mode is hiring, since it's
"started production of a new full game based on the cutting-edge Doom 3 engine... in a continuation of our successful collaboration with id Software and Activision."