Aside from peripherals and game consoles, Microsoft doesn't design hardware – at least not complete PCs. But found in the leaks of Windows 8 is a concept design of an all-in-one PC that Microsoft figures would take advantage of the new OS features.
Notably is the multi-touch screen that's able to resolve at least five different points and the mandatory DirectX GPU for HD video. The all-in-one would also pack things that machines don't have these days, like proximity sensors (for automatic sleep and wake), light sensors (for automatic brightening and dimming).
Check out the full slide below: