Still Very Suspect
I wasn't convinced by the original photo, and I am still not convinced by this new video. That said, I had a feeling the first photo was "real," in so far as it was an unedited picture of an actual physical object. I think this video is also "real" in the same way.
Still, none of this adds up. Consider the following points:
1. The Mac mini has had the same chassis design since its debut in January of 2005. Four years is an eternity in the world of Apple, and with everything moving towards aluminum with black accents, it's hard to believe that Apple wouldn't at least give the machine a black matte plastic top.
2. FireWire 800 doesn't make sense on a low-end machine. Or, for that matter, FireWire 400. Apple has dropped FireWire from the MacBook and it just follows logically that they would drop it from the mini as a cost-cutting measure. And it's largely unnecessary for switchers, who are unlikely to have FireWire devices; USB 2.0 has much greater penetration in the PC market.
3. All ports on Macs are bottom-justified, in line with the logic board. The Mini DVI and Mini Display Port on this machine are center-justified, suggesting they're elevated off the logic board. This makes little sense.
4. The person who offered up the photo and then the video has not provided us with high-resolution photos from differing angles. This is VERY suspicious. If he has the machine in his possession, and is so happy to show it to the world... how hard would it be to take a high-resolution photo of it? It seems highly unlikely that a person with access to a pre-release machine would not have the resources to take a quality photo. Decent digital cameras are, what, $99?
5. The most damning evidence of all: Apple doesn't care. If this was a pre-release product, you can be sure Apple would be sending cease-and-desist letters to every major site posting the images. And, yet... it hasn't.
So, what is it? I have no definitive answer. It could be an old prototype. It could be a case mod with a MacBook Pro stuffed in it. And, you know, it could be the new Mac mini.
But I don't think so.