Lucky old Voodoo Extreme have posted an interview with id Software's Kevin Cloud about Return to Castle Wolfenstein. Heres a snip:
Voodoo Extreme -- Besides human Nazi soldiers, we've seen screen shots of undead and other monstrosities. What kind of monsters will BJ have to blow away (forgive the pun).
[Kevin Cloud]: This is really one of the best things about RTCW. Working in the Wolfenstein universe and with the story that we've developed allows us to have the game set in a familiar setting (i.e. WWII), with traditional enemies like Nazi soldiers, SS Elite Guard, and others. However, through the genetic mutation, experiments, occult overtones and raising of the dead, we are able to add some incredibly creative enemies like the zombies, zombie knights, and x-creatures. The game is an interesting mix of Indiana Jones and X-Files where the player is in relatively familiar surroundings, but for periods of time must deal with completely strange and bizarre situations, which are particularly reflected in the enemies.