CRITICALThinker :
RedJaron :
Windows Continuum already uses the phone as a trackpad.
Does it now? haven't checked, and last I heard about continuum was for the hp elite phone, which did not incorporate the phone into the chassis when using the laptop.
The Lumia 950 can be a trackpad. You can actually use a mouse with the phone even when it's not hooked up to an external display and get a cursor on the phone's display.
To those complaining about most phones being ARM instead of x86, that's not an insignificant point. However, going back to my Continuum reference, you can get perfectly functional MS Office on ARM, as well as many other applications that can be very productive. It's not perfect, but for people doing basic productivity computing, it's adequate on the go.