Heading into launch of the iPhone 6s/6s+, the analysts were projected the first YoY decline in sales for the iPhone. However, Apple threw everyone a curveball with 13 million sales. It seems that in response, people are trying to find ways to prove that iPhone sales are actually slowing down by any means possible.
The strong argument appears to be that the increase in sales was almost completely attributable to China. People are saying that last year, the iPhone 6/6+ wasn't available in China so China has to be excluded in order to maintain and apples-to-apples comparison. If that's the case, then could one extend the argument and say that in order to improve comparability, sales on other carriers should be excluded from YoY comparisons with USA sales because in the beginning the iPhone was availably only on AT&T? So what if China helped Apple sell more iPhones?
That's because each year for the holiday quarter Apple manages to come up with some new innovation that gets people very interested in iPhones again. This year it's 3D Touch.
2010 - Retina display
2011 - Siri
2012 - 4" screen & Passbook
2013 - Touch ID
2014 - Larger screens
2015 - 3D Touch
Apple has a proven track record this decade of having at least one HUGE innovation in the iPhone each year, thus conditioning the consumer MIND. Thus analysts should at least wait until a couple of years go by without innovations before predicting a fall-off in sales. With liquid-metal, water-proofing and other things coming down the pike I thing there are no shortage of big innovations to catch the consumer eye in 2016 and beyond.