Tactile feedback is critical to a satisfying, accurate typing experience. I'd wager a lot of people buy macbooks instead of ipads just for that experience, myself included. I'm looking at patentlyapple.com and they have a lot of ideas w.r.t. future mac keyboards. An interesting one that I see is the carbon fibre keyboard:
https://www.patentlyapple.com/paten...that-could-eliminate-the-butterfly-hinge.html
https://www.patentlyapple.com/paten...that-could-eliminate-the-butterfly-hinge.html