My state has digital insurance and registration cards. I guess this is the next logical step.
But I do worry about when people get used to using these digital identification and then get pulled over after their phone battery dies or when their phone breaks on vacation or something.
A simple traffic stop with a warning suddenly becomes a day in jail while the police "verify"a person's identity.
There was a case in the UK recently where some one got a £500 fine on the train because their phone died and they could not show their electronic ticket.
I was only after the press got involved that it was over turned.
As a CO resident I haven't really found a use for it yet. There's even a disclaimer to take your physical ID with you wherever you go.