[kaolinite]

I'm on mobile so not sure if anyone else has pointed this out but Apple mentioned in the keynote that the escape key is still present when using the terminal. There is also a way to bring up the full row of function keys.

Personally I think this is the great advantage of the touch bar. The only app that I personally use the Esc key in has it available, but all other apps use the space for more appropriate shortcuts. Plus it can be customised too (finally I can add a screenshot button!), although not per app yet, as far as I can tell.