Just received my Zombie Bait Edition, and the slipcover DOES have the Xbox 360 band around it.
However, when the slipcover comes off, the box is unbranded, so I believe that any "PS3" copies that are kicking about are actually just swap outs. As the unboxing that was posted a few pages back of a PS3 version, didn't have a slipcover if I remember correctly (although the video has now conveniently been removed from YouTube
) xx