Well since someone started this topic on it again i have also a few question of my own.
Say we are getting a Small form factor PC. There are a few point that i myself cannot conclude and like to point out and share if possible to have the best possible option.
Mini-ITX board that have Wi-fi card inbuilt cost a premium way larger than having a Micro-ATX board and placing in a wi-fi card through PCI/PCI-E.
On-top of that if you are using it as a streaming device for your TV/HTPC. I expect it to be in for the long-haul. Around 5 years or longer. Which means there is bound to have a motherboard replacement somewhere in between.
Now there right away, i will have a problem, i might not be able to find the same motherboard of Mini Version that carries in built wi-fi. Especially when we come to Intel, when there is a board refreshment every 2 cycle.
However, the mico-version will likely be available. (PS i just got a replacement board Micro-ATX one for my Q6600 just around this year)
So what i deduce from the above is that i need a small-form PC able to take in a Micro-ATX, even if i am going for Mini-ITX board. As a contingency plan, else risking getting another casing 3-4yrs down the road.
So from cost and maintenance perspective, Micro-ATX board have an advantage and flexibility right off the gate.
However, if i am purely going from that train of thought i would have very full choice of small form casing left.
The only one i see so far that fill this is cooler master Mini 210.
Edit: Also include InWin BL Series.