also, that new "press the wake button 5 times and then hit "cancel""-mechanism to switch off biometrics wouldn't work in a situation where your phone gets snatched by someone else. personally i wouldn't worry about that fringe case when law enforcement wants your data - there's a passcode for that - but for spouses or children getting easier access to your pivate data or the app store than with touchID.
I agree - my concerns are how will this be implemented? Auto unlock opens up a whole can of worms' the LE comment was its one case where it would have significant impact on one's 5th amendment rights in the US.