Bad news if you were planning on co-op-ing some Duke Nuke 3D on Xbox Live Arcade this Wednesday when it's released with your buddy over in Japan.  According to George Broussard's Twitter the game has been given an Adults Only rating equivalent there and therefore will not be released via Xbox Live Arcade in the Japanese region.

There's no word yet on whether or not they will appeal the rating.   As far as we can tell the original game was never "banned" in Japan, and neither were the successive ports of the title on the Nintendo 64, PlayStation and SegaSaturn; though these versions were all tamed down in some manner.