So I have inherited my wife's 2 year old Surface Pro.
Does anyone know of useful ways to integrate something like this into their home studio?
I'm at a loss. Was thinking maybe as a controller via bluetooth.

if you find configurable controller software (i'm sure there is some, and someone will soon point you to it), you could set it up as a control surface for certain tasks ...
 
I wouldn't use bluetooth, though, as BT reliability is annoying at best ... you could plug a cheap ESI MIDIMATE into the USB port and have it communicate via MIDI
 
 
EDIT: just realized that it comes with a full windows 8.1 (not just win RT) and has similar specs than my Acer tablet PC, on which I run the full Sonar version for live playback / recording multitrack demos ... so you'll find plenty of use for it.

I use my Surface Pro 2 to control my interface (XR-18) via wireless connection.  Works great!  I can also connect via USB and do 18 channel recording...
My Surface Pro is i5 with 8 GB Ram and 256 GB hard drive.
 

Website dedicated to using the Surface Pro in audio production:
 
http://surfaceproaudio.com/
 
Same guy's YouTube channel:
 
https://www.youtube.com/user/MoltenMusicTech/videos

Thank you so much for your input.
Really appreciate this.

I've been toying with the idea of using one of these cheap Win 10 touch laptop/tablet combos as a remote control surface. Is there any software for Windows that will do this or is it all on iOS/Android?

I use my surface pro as my main daw. Have been using it almost for 2 years.

It is a very capable machine... I even have a bt mouse and keyboard connected to it. The wifi stays on and haven't experienced any of the weird update troubles some are having.