When I say tipping point, I mean when Android will outsell iPhone (not the total devices in the market, but the number of devices sold in that quarter) in one quarter in US. This tipping point should come very quickly barring Apple pulling something drastic (like opening up iPhone to carriers other than AT&T)
Since early 2009, I have believed that Android will eventually surpass iPhone. That belief has not changed.
The combined innovation of multiple players will eventually overtake one single company. As long as Apple's iPhone remain a closed system, the result will be inevitable. The history will likely repeat itself.
Let's look at the PDA market in the past. At the time that Palm has 90% market share, I believed that Windows Mobile (at the time called PocketPC) will eventually overtake Palm. It may take a long while, and it did take several years. But Microsoft eventually was able to overtake Palm in PDA area.
However, I cannot say that my belief at that time is correct, at that time, I based my belief on gut feeling alone. However, looking back, it appears that several signs were already present at that time that partially foretell such outcome.
It seems that when a new thing is introduced to consumers, it must be very simple to use for it to catch on. Palm was a master of that. However, as time goes on, people demanded more choices, options, and functionalities. aThat is where the combined industry ecosystem comes in that can overtake a single company. In another word, smart phone market would have been as vibrant if it wasn't for Apple's iPhone. iPhone is a superb devices to convert users to smart phone users, but it also opens the door for the users to accept other smart phones. And that is where Android can excel eventually.