Well I've seen attempts, overall the outcomes were a lot less sexy / not worth the hassle imo. Nvidia has ~500$ set-up described
somewhere on their website, it is not that different, yet it doesn't include the pad+receiver, Windows, form factor is bigger, etc.
That things is incredibly tiny, and yet it is not noisy either, I would trade that small amount of extra power one could get from going with AMD parts for the huge saving in heat/power consumption, impact on noise and most likely form factors.
Really it is a good set-up, some harsh reviews just goes on showing how ignorant and opinionated some reviewers are, that things is priced lower than some Brix gaming set-up without the pitfall (power, heat, noise).
I hope it starts a trend, I want to see more desktop built with laptop parts, geeks are fine with it but I find less and less "average" people that are fine with the form factor/utility ratio of those decade old tower design, even for gaming purpose. If MSFT want to move desktop (and so Windows) to customers they better encourage that type of initiatives (even if it competes with the One).