Here's the picture of Surface featured on Microsoft's site:
Made of magnesium it's extremely rigid and light, only 1.5 pounds, and thin. Screen size is 10.6" (16/9 format) compared to iPad's 9.7" (4/3 format).
Looking at the picture you might think it's an extremely thin ultrabook, which is a class of thin laptop PCs from the major PC makers. That's because the picture shows the Surface with one of the protective covers (can't see which one).
There will be two different protective covers, both with keyboards. One is the touch-cover and the other is the type-cover. They connect to the device via a magnetic connector. The touch-cover has a touch-sensitive keyboard while the (thicker) type-cover has a more traditional keyboard.
For hands-free viewing in landscape mode, Surface has an onboard stand, which is extremely thin (0.77 mm = 0.03 inches).
The covers seem to be important to the Surface designers. It seems they intend the device to be two things, namely a laptop and a tablet. With the covers it's a laptop and then you'll be using the onboard stand, which angles the device 22°. I wonder if 22° will suit every user or if there's some elegant way to modify the angle.
Microsoft will be making the Surface and the reason is probably that the Surface project is older than the partnership with Nokia. I suggest Nokia should be invited to join the Surface project. To many people that would amount to a guarantee that the hardware quality is Ok and say, thermal breakdowns wouldn't occur.