With the exception of the folks doing keyboards (which they have been serially been screwing up for the last ten years) Microsoft has some very good hardware people. The Surface was a nice piece of kit, but way expensive (for unavoidable reasons, I hear) and running the wrong software (also for unavoidable reasons).
I remember their developer evangelists were running around showing off some $3000 Samsung tablet PC prior to the Surface and Surface Pro being released.
People think the Surface is expensive because they compare it to the iPad or Nexus 7/10 product lines, but it seems like Windows RT is closer to a port of Windows 8 to ARM than anything else, which makes it seem odd that you'd think to run Windows Rt on a $200 tablet.
But now they're in control of a hardware vendor - one in a position to allow them to close off WP8 to other OEMs, and potentially a future version of Windows.