Here's a gallery of photos:
As you can see it has the docking port, rear camera, and 2 speakers that have shown up in past leaks.
But it also has an oddity on the base of the home screen. Do you see the 3 icons? That is rather interesting because the iPad defaults to 4 icons. But you can add or remove the icons, so it's not impossible that this iPad Mini was customized by the user. If anything, this detail makes these iPad Mini photos more credible, not less.
So I would guess that this is proof that the iPad Mini does exist, and it seems a near certainty now that we'll see it launched in October. I will be ready to buy one, definitely.