I kind of think the duct tape of tomorrow will still be duct tape. Its beauty is its simplicity. Oddly enough, the one thing you can't use it for are HVAC ducts -- they use a metallic tape with a different adhesive for those.
The fully-evolved, end-state smartphone will absolutely have biometrics as a standard feature. That's far too useful to far too many people for it not to happen. Things like radiation meters might be standard ... that seems farfetched, but hey, I'd have called you a loony if you'd told me ten years ago I'd be carrying a barometer around in my shirt pocket today, yet here we are. The trick is going to be fitting all of the features into a form factor the consumer finds acceptable, while not having it become buggy and unreliable.
