One by One, Two by Two

I'm not sure what Apple 'invented' with the iPhone.    They did not invent the touchscreen or a full screen touch interface.   I had an MDA in 2005 that was essentially a thick iPhone.   It had a full size, 3.2" screen touchscreen etc, etc.

They did not invent the smartphone, blackberries had been around for a while, and actually palm has the patent on the smartphone.

The original iPhone lacked key features that were standard at the time, MMS, 3g, video and a LED flash, etc etc.

So the question is WHY was it so popular?   The competition at the time was the Tilt  or the blackberry 8320.

There are two correct answers.
1) design - Look at the original iPhone, then look at the two monstrosities posted above.   enough said.
2) They are apple - I have long said that apple could invent an iBrick, and people would flock to it as the best brick available in the world.

Regardless, Apple's lead in the full touchscreen smartphone market has been enormous for some time, however one by one they are losing those leads

Android overtook iOS in terms of sales last year

I believe the Galaxy Nexus has overtaken the Iphone 4s in the "phone to compare to category"

Today it was announced that Samsung overtook Apple as top smartphone manufacturer.

Here are some other things Apple is about to lose/may lose.  
-Total apps in app-store (early to middle of next year)
-Maybe someday in a couple years they will lose top selling phone to the galaxy S 5
-Best selling tablet OS -Android jumped 27% in one year