1.) Why would anybody need 5 USB ports?
2.) In regards to the video connectors, it seems unlikely that Apple would invest the additional time and money to include legacy hardware, particularly when they've made such a to-do about their new standard, not to mention that they make an adapter for this purpose.
3.) Firewire 800 is not all that far-fetched, seeing as the current mini includes the FW standard already. Backed when I worked in TV, we used Minis exclusively to digitize DV tapes, which has to be done in real time and doesn't require all that much processing power. All our hard drives were FW, so I can see them including the standard just for good measure. I know it's been phased out o on the MacBooks, but those are in a slightly different category. If Apple wanted to, they could make the argument that anyone needing a mobile work station to do video work will also likely need the added grfx and processing power of a pro unit anyway. While I know it's possible, I've never actually *seen* anyone edit on a standard MacBook. The mini, however, can be used as a low-cost alternative to augment your post production facilities, as was my experience, so it *might* still serve a niche there.
My inclination - at least my hope - is that this is likely just a prototype and not the final revision. I'd also be somewhat surprised for the Mini not to support a black enclosure to match that of it's bigger siblings. It would make very little sense design-wise to do anything other wise. I'm sure the mini is forthcoming, but I hope it's a little more fresh than what we see here.