Bear in mind, Apple is losing marketshare with 1.5 and 2 yr old products - but they are estimating 50 Million iPhone 5's by the end of the year.
Even the bump when the iPhone 4 was released didn't stop the ascent of Android. Android is now over half the market in the US, and about the same worldwide. Apple simply cannot compete against the slew of options from other manufacturers.
Want a physical keyboard? No Apple. Want a screen larger than 3.5"? No Apple. Want 4G? No Apple. Want an SD card? No Apple. Want widgets? No Apple. Want to play WMVs or WMA media? No Apple. Want 3D? No Apple. Want a smaller than 3.5" screen? No Apple. Want a world phone? No Apple.
And on and on... You can find all those options with other brands. For example, I want a world phone (Verizon in the US/CDMA here, GSM for overseas). There is ZERO Apple option for me. And I'm not willing to sacrifice because at my house in the US, Verizon is the ONLY carrier that has good coverage (literally - friends with Sprint and AT&T phones get zero coverage here, I get great Verizon coverage). And when I travel internationally, I like to pop in one of my SIM cards I have, so I can activate my "local" number that is cheaper.
There is NO Apple option for me - I cannot even consider it.
Apple's strength is its slavish devotion to getting a small set of features perfectly right on one single hardware platform. That necessarily restricts choice and options, and makes it hard to maintain any kind of significant marketshare.
The only reason Apple is seeing quarter-over-quarter growth of iPhone sales is because the market as a whole is growing faster than their slide of marketshare; once the US and EU markets start to saturate, and the growth moves to Asia (where Apple is simply too expensive for most of the market - SE Asia and India and most of China), you'll see Apple's sales start to slide down as well, with their marketshare.
The aberration is that a single phone with a fixed set of functionality managed to burst on the scene and grab so much marketshare; long-term, it'll slide to the 7-10% of overall marketshare where one would expect such a phone to really exist.
but they are estimating 50 Million iPhone 5's by the end of the year.
Yeah, I don't buy it. Less than 3 months of sales (announcement in October is the rumor), 50 million phones? That's 20+ million a month. That would triple the peak sales of phones that Apple ever had. Wishful thinking - I don't think they could even make that many.