The surface (that you write on, the wacom tablet/wacom screen) has tech in it to know where you are pressing.
The pen says how hard. You need BOTH for it to work.
So with the surface (microsoft tablet) the screen knows where you are pressing,
therefore all you'd need is a pen to talk to the tablet, as microsoft is all for styluses then it COULD happen!
The closest the ipad can get is a pen that makes sound noises to talk to the ipad, and an app to work with it; that is the problem. for microsofts tablet the stylus stuff can be across all of the OS and not shoehorned into one app.
Hopefully microsoft or even wacom will push for this, but seeing as how the Microsoft Courier was cancelled, i wont hold my breath.