Microsoft has been trying to sell stylus based tablets for years, and they never stopped: Windows for pen based computers, Windows XP Tablet PC Edition, UMPC, Courier, Slate PC, etc etc.

I'm all for experimenting by releasing products in the wild, hoping that the next iteration will finally find its market. But seriously, it's getting a little ridiculous.

http://en.wikipedia.org/wiki/Microsoft_Tablet_PC#History