While it's entirely possible that EGM knows something we don't and inadvertently let the ninja out of the bag, I dismiss this idea for one main reason: Microsoft is publishing the game. Unless Tecmo and Team Ninja decided to let Sony or someone else (maybe themselves) publish Ninja Gaiden II for the PS3, I doubt the game is coming to the PS3 by way of Microsoft.
Then again, maybe EGM does know something, but they aren't allowed to say, in which case they "accidentally" listed the game for both consoles. Again, I find this very hard to believe. They would all be killed!