I mean, it pre-dates COD5 by a year, Dead Snow by two, and basically seems to have invented an entire subgenre without getting any credit for it. Madness.
Well this game http://www.giantbomb.com/return-to-castle-wolfenstein-tides-of-war/3030-3719/ came out in 2003 and had Nazi Zombies, but I wouldn't say this was the first either. I'm sure there is others.
Well, I´m pretty sure the whole "Nazis dealing with the occult" thing has been around for a while. I think Return to Castle Wolfenstein had a lot of that stuff in it. But the exact concept of "Nazi Zombies"? I don´t know. There were zombie like creatures in the crypts, but they were from a time before Nazis :P
Maybe some other games did it before?
@white_silhouette: I don't know why I never thought of that.
Even so, the whole thing seems to have become less sparing in the last few years, and Operation Darkness seemed to be ahead of the curve on that. Alas it never came out here, but I remember reading reviews saying it was at least an unusual premise, which I wouldn't say now.