I've been using my iPad with a BT keyboard, and one of the thing that excites me about the Surface is that the OS is actually optimised for both touch and keyboard use. With the iPad, you can type text and use a couple of system commands (homescreen, brightness, music controls). But you still have to reach up and swipe through apps and touch the app you want to load, swipe to shift between apps, etc etc.

But with Windows 8, every touch gesture or feature is baked in intelligently to keyboard/trackpad use. Swiping between apps, bringing up charms, splitting the screen, selecting tiles on the start screen, etc etc. I think this will make a huge difference. Microsoft has an advantage here because W8 has been built simultaneously for all of these usage models, whereas Apple started with touch and is still tethered to a fingers-only UI basis.