What is the purpose of instrumentation console introduced in Summer'16 lightning view and how can this be used in development process ? There is no mention of this in the Summer'16 release notes also.
You can record your interactions and play them again to see the stats, you can download the JSON format of the interaction from right bottom corner icon, you can also load interaction files. And in the View Waterfall option you can see stats for the transaction and when you play the recorded interaction you can see in different views as chosen in I want to ... dropdown.
Hope this helps to give an idea what is it for.