I remember using an early version of OneNote back in 2005 when I had a Motion Computing LS 800 slate pc (way ahead of it's time) and it quickly became my most used app, especially in combination with a couple power toys that are now integrated into the software.
"That meant supporting text and keyboards, since the Tablet had not even shipped yet and would have very small share when we launched, although we all suspected at least the ability to write on the screen would become a ubiquitous laptop feature eventually. And ink would never replace keyboard - the pen is useful for some things (quiet, unobtrusive, natural), and the keyboard was better for others (fast, compact, accurate input). Of course the Tablet was a key factor for us - we wanted to make sure we made a great application for all PCs, and since the Tablet (with a keyboard) was a superset of other PCs, we would be most powerful on the Tablet, and ideally a “no-brainer” purchase for Tablet owners."
This quote kind of shows how far ahead Microsoft, and the brilliant people they have working for them, were in their thinking. They have been improving tablet support in Windows for a decade, with each release it got significantly better. Windows 8, although some people would like to complain about it being too big a departure from the Windows they know and love/hate, to me seems just the logical progression they have been working toward for years.