Just for fun...
Just for fun, lets assume the photo is of a real Mini.
Why 5 USB ports?
One port for the keyboard/mouse.
One for a printer.
One for a camera/scanner or other image capture device.
One for an external HD.
One left over.
Except, it makes more sense for Apple to eliminate a port or three, and download the cost of hub to the buyer. So, why 5?
It makes sense for devices for which it doesn't make sense to use with a hub, including reasons that have an aesthetic design.
I don't have all the answers, so I will start just to get the ball rolling.
Apple is going to introduce devices with the same footprint as the Mini, and that are meant to be stacked under/over - similar to the NewerTech drives. The design consideration is that the cord that connected the two would be neater if it was short and bypassed a USB hub. So, what kind of device? Time Capsule perhaps, or an external HD meant to work as a media server? Would a USB connection be adequate?
With that many USB hubs, you could stack a couple or three together.
Another possibility are Apple devices that require more power than an unpowered hub can provide. Again, design aesthetics might be that Apple wanted to minimize cord clutter, and so built the Mini to power a number of devices. Again, any ideas?
How about if the Mini can be used as a smart USB hub? Have we got an sense of size yet? What if it actually grew slightly so that it stacked on an Airport Extreme Base station? Connect the two with a short USB cord, and you lose the USB port on the AEB, but get 4 more on the Mini. Is there something in the media server area that would make sense to do this? I don't know why a smart USB hub might be needed - any ideas?
What if one or two of the USB ports were USB 3, and the rest USB 2. Then you could use old/slow devices on the USB 2 ports, and still get full speed on the USB 3 ports. It would very feasible that early product packaging and prototypes might not have the USB 2/3 distinguishing marks.
Personally, I find the mock ups so far less than compelling. But for fun I thought I might start speculating.
Cheers
Sympathies to my American cousins in the NE.