This already happened. inXile made Torment: Tides of Numenera.
Not sure if it is any good though - I still haven't played it.
I liked Tides of Numenara quite a bit actually, but it didn't really feel like Planescape: Torment, IMO.
It has fairly bad combat, so whether you like it or not will depend heavily upon whether you like the copious amounts of dialogue. I did, and hence enjoyed the game, but the steam forums at release indicated that many people loathed the writing. YMMV.
