I don't know what it is, and with only a few days left to wait, frankly I don't care, but I can tell you what it isn't.
It's definitely not Photoshop. Everyone so far who's pointed out their "unmistakable evidence" has only shown their lack of understanding of the program. Or photography. Or digital imaging in general.
It's not perfectly straight, of course not, it's a portrait-oriented center-crop from an extremely close-up landscape-oriented picture, from a lens which probably doesn't have much in the way of distortion compensation.
And the chromatic aberration around the Apple logo? Perfectly consistent with how a point-&-shoot clips highlights.
Zoom into your own pictures, people. These artifacts are everywhere, symptoms of cheap sensors and poor optics, not Photoshop.
In fact, if this is Photoshop, it's extremely well done; the photographic mistakes are so convincing, that it would have to have been done by someone talented enough that it's unlikely they'll be decisively busted by the caliber of detectives that have posted thus far.
(after re-reading my post, this all comes off a lot more condescending than I am in real life, but there isn't an emoticon for hey-I'm-not-calling-you-dumb-but-dude-you're-only-finding-evidence-because-you-want-it-to-be-there-to-support-the-conclusion-you've-already-made.)
EDIT: looking at the thing again, it does look funky, but not PS funky. I have a hard time believing this is even an Apple prototype, so much is wrong (but what do I know, maybe their mock-up standards are not as high as Steve would like), but somebody made this. In real life, with half baked FCC ID and part number too. Couldn't guess why, unless it is Apple. Maybe it's a reject off the prototype production line and that's how it fell into enemy hands?