One point which I haven't seen anyone else bring up on this thread is that many (maybe most) people will need more than one adapter even for just one phone.
I have a charger at home, a charger at work, and a USB cable in my car which I sometimes use for a top-up.
Unless I want to carry a single adapter around with me all the time (or just leave it connected to the phone... yuck) then I'd need three adapters.
(sigh)
The next iPhone may have a different dock connector on the
head-end of the cable... but that won't affect charging.
The
tail of that cable will still be good ol' USB... so all your
existing USB chargers will still function at home, at work and in your car.
Nothing is changing on the tail-end... so don't worry about not being able to charge your new iPhone. You've probably got plenty of USB chargers... and you'll get yet another USB wall charger with the new iPhone.
And it won't be too long until Monoprice has new iPhone charging cables for $3
The real issue here is about speakers and accessories with a hardwired 30-pin dock. Those will need some kind of adapter if you want to use them with the new iPhone.