Fake. Very fake. And not particularly difficult to do. Just take an iPhone photo, do a little photochopping, layer one on top of the other, display it on a CRT and take a photo of it. Wow.
How do I know it's fake? Lots of reasons, but the most important of which is common sense. Apple has no compelling reason to produce an iPhone Nano in the configuration shown here. Judging from the icons, it's got all the same features as the standard iPhone except a screen that isn't is tall, in a smaller form factor. Why? WHY??
Of all the iPhone complaints I read over and over on the web, I very rarely see anyone say "I love the iPhone, it's well worth the money, I just wish it wasn't so damn BIG".
Here's what I do read a lot: "The data plan is a killer".
So here's what DOES make sense to me: A smaller, less expensive iPhone without full data functions. Basically an iPhone feature phone, instead of a smartphone. Think Apple's version of an LG Dare. It has a nice touch screen, all the iPod music and video functions, basic email access, a limited WAP web browser, and a limited app store.