I'd think fake... those shadows do look suspicious, and besides, it'd be pretty easy to do this sort of thing, I'd think.
Furthermore, even if it were real, I'd be disappointed. Of course the nano would get wider for a wider screen - that cannot be helped. But slim things fit better in the hand and are arguably more pleasing to the eye. Consider that, and then that the nano having a small screen is part of what makes it a nano and not a video iPod. That is, unless the video iPod sees a much bigger screen, of course.
Still, probably fake. All iPods are accessories in addition to being music players, but the squarish look won't cut it in a nano.