I do think that if at all possible, Apple has to think about moving to a twice a year roll out of phones. that would smooth out the demand curve a bit IMO.
Apple -- Consider that Americans are locked into carrier contracts of 24+ months. If they all bought the 5S when it released, it isn't financially feasible to purchase an iPhone 6. Those still on the 4/4S, and early 5 adopters need to be the target for the 6. Don't let "waning" 5S sales delay the release of the 6 - it'd be moronic and keep us who've been holding out from getting the phone that we need NOW.