I think a silent upgrade of the mini is most likely and possibly best option.
While it may have seen a bigger change if Broadwell were available (ie a better CPU than whats shipping this fall), Haswell is all there is and our friends at Apple will surely want an entry level, relatively low price point, small form factor desktop to drive new displays which are likely to be announced this week and probably ship before Christmas.
A single TB1 port and HD4000 integrated graphics will not do.
The relatively minor changes I anticipate are probably good news since form factor stays the same with replaceable SATA HDD and RAM that is not soldered at price point about the same as today's Mini!
I wonder if this won't be the last Mini and the tag line refers to a more capable Mac that is the elusive xMac aimed at enthusiasts / gamers / professionals with no need for a nMP? This new Mac could be announced this week but ship in the new year with a Micro Mac computer (fanless with Broadwell, soldered RAM, etc) aimed at the masses for home server, HTPC, surfing, etc! If Intel weren't so far behind rolling out Broadwell, then I doubt there would be a 2014 Mini at all since I think Apple only see it as a bridge.
With gaming being so huge (the amount of money involved is staggering), I find it hard to believe that Tim wants to be sitting on the bench. While a new Mac may not drive huge profits, surely there is a way to profit off the games themselves?
That's my 2 cents.
Cheers