I don't see whats the point of removing the buttons
The raw button is about as useful to me as Canon's direct print button. I'd much rather have a raw quality button.
and having exchangable sensors.
You could have a 50mp low dynamic range sensor for studio work, a 10mp high dynamic range sensor for snapshooting, a sensor optimized for IR, etc, you could choose between sensor technologies like Bayer, Foveon.
By the time you need a new sensor might as well get a new body right?
Why in the world would you want an expensive new body when you could just buy a new sensor for 1/3 the price?
A fixed sensor is like a film camera that only takes one specific film.
How much are you willing to pay for that?
If it were released tomorrow? I'd wait five years and buy it for $1000 used