Surface already comes with Wacom's digitizer technology so you can get pressure sensitivity and all that good stuff. You probably just need to buy the stylus.
Sketchbook Pro is a desktop-only app; you are probably thinking of the metro version of Sketchbook Express.
Microsoft's own Fresh Paint app is another one that could benefit from this. One thing to note is that all of the Bluetooth styli released so far on iOS are exclusive to Apple's platform. An exception is Hex JaJa, which is cross-platform between iOS and Android, but it's not a Bluetooth stylus either - it utilises high-pitch sounds delivered via microphone.
Yes, I was simply saying it'd be nice to use this stylus on Windows with Photoshop because of its physical/aesthetic characteristics. It doesn't add much technically over the Wacom stylus, might even be slightly inferior, but it will feel different in the hand.
