... Putting Touch ID on the lock button automatically creates a three step process: Pick up your phone, Authenticate with your finger, then press the home button to enter your homescreen.
A simple update could make the phone automatically unlock to the home screen once your finger print is authenticated. The phones already wake when you pick them up, so simply placing your thumb to the side actually removes the need to click anything.
Changing the dynamic on how we unlock won't be to hard considering when you look at the front of the phone there won't be a button to press.