Man, judging by such mythical stuff as the "Courrier Tablet", that cool "Surface" whathchaisit, and a host of other theoretical stuff i hear all the time, i would venture, as weird as it might sound, Microsoft Research...
There's Microsoft's problem right there, they can't ship innovative, risky products, due to their overdependence on the twin Windows/Office franchise. Classic case of Innovator's Dilemma.
I think it is microsoft as well. The bureaucracy shoots down any good ideas, so the inventions languish. Just like at xerox parc