I think it is extremely hard to make Windows "true" tablet friendly. Mainly because of the backward compatibility. I really don't understand why Balmer would want Win8 as front of the tablet market when WinPh is a much better and obvious choice.
To my understanding, people use tablet only check website, stream videos, personal notes, and other non-business non-work related tasks. Non-work means it is not something like turbo tax, your own expense sheet, etc. Non-business means it is not for business routines, dose not include "Sales Rep" where they need to show off with finger friendly power point slides.
I understand Windows itself needs to catch up, but, that would be very challanging and takes much more time. They can think about merging the tablet specific os back to Windows (since same SL) later. But, they got to take the market right now. It is like Win95 and WinNT, you need two families before you can merge them together. They should start a new branch and merge it back later.