A spec sheet leaked a couple days ago which detailed the not yet released Xbox Surface. I saw it yesterday, and I initially held the post so I could use the info to support the big news announcement last night. I'm glad I held it because it turns out that the Xbox Surface probably has very little to do with the event last night.
A number of sites reported on the Xbox Surface yesterday, and some called it a tablet. That's not quite true. A close reading of the spec sheet suggests that the Xbox Surface isn't a tablet so much as it's just a wireless controller for the next Xbox. Have you seen photos of the new WiiU controller? While we don't know what the Xbox Surface will look like, we can guess that it will work much the same way as WiiU controller.
The spec sheet indicates that the the Xbox Surface has a 7" (1280x800) screen with card slots, Wifi, and Bluetooth, but what it doesn't have is a CPU. That is in the "stationary computing device", which in fact has 2 multi-core CPUs as well as 5GB of RAM and an unspecified graphics chip.
Don't get me wrong; I think the Xbox Surface is going to be great - assuming this spec sheet is for real. But the important thing to note here is that the Xbox Surface isn't going to be competition for the Windows tablets announced last night - not in any form. Those are mobile devices while this one is fixed. Microsoft is quite carefully not letting their 2 products get in each other's way.