In order for the pressure sensitive table to be any good for serious artists it would have to be bigger than 10". My wife does work on 1.2GB photoshop files and her 21" Cintiq doesn't even feel big enough.
Microsofts tablet is too expensive to be a toy and too diminutive to be a production machine. I can't think of anything serious that I'd want to do on a 10" M$ tablet. If it's something quick like browsing/email then an iPad would be better. If it something serious like graphic design or programming then I want a bigger screen.
It's for OneNote. Which is rediculously good, but has always been constrained by only working on crappy hardware.
OneNote for the iPad would be insanely big if it had proper digitiser support.
As for this? Hardware wise it will be fantastic in two years. Intel are about to crush everything in low power chips, and the digitiser is a real killer app.
The problem is that Windows 8 remains two OSes bolted together, rather than one good one that works for touch and mouse work. But the vision of looking at something on a laptop and being able to carry it around as a tablet to finish reading in the kitchen is absolutely compelling - I wish my Air was able to do that all the time. But it needs to run a proper, coherent OS in both scenarios.