Great article Andrew.
I just wanted to add that press and hold buttons are already working as the future of confirmed action.
One such example is the end-run button on nike+ running app. The problem in most running apps is that the end run button is unintentionally pressed while running and defeats the entire purpose of the app as the app stops working in the middle of the run. The worst part is that the user gets to know about it only at the finish line.
To solve this, the new button on Nike+ is a kind of a press and hold timer which needs to be pressed for 2–3 seconds continuously before the run is finished.