While I did see some function in some of the demos, others left me thinking the touch bar UI is a confused mismatch of an interface. Rotating objects with a touchpad seems unnatural compared to multitouch on the screen.
It's completely customizable, so the user is ultimately in control of what appears there. Apple is basically providing people with a vastly superior set of function keys, and I think most people would probably agree that many of the functions that are currently on physical keyboards are fairly awkward and limited compared to this.