My neighbor got an Asus Transformer (the T300 model or what ever it was called). It's definitely slick and I could type quite well on it. Can't wait to see how the Win 8 RT app ecosystem plays out, because I like a lot of things MSFT is doing with their multi-tasking and side-by-side apps. Having good multi-tasking hot-keys on the keyboard is a big boost in productivity. Get me a good RDP client on it and I could find it very useful for a lot of work scenarios.
Surface (with its kickstand) + thin keyboard cover is an advance on that. You've got something that folds open and closed like a laptop, but is about the same thickness as iPad+smart cover.
It's a little bit like comparing the first truly practical cars (Model T vintage) to the very first cars and saying that they haven't done anything revolutionary.