There is an interesting article
in today's Business Section of the New York Times that asks the question of whether Apple's business culture with respect to the iPhone is taking it down the same path it went down with respect to the Macintosh which saw it eventually lose out to Microsoft in the market for home computing. This question refers, of course, to Apple's culture of control over the market for apps on the iPhone, which is reminiscent of its demands in the 1980's and '90's that application developers wishing to write code for the Macintosh had to apply for and pay for licenses from Apple before Apple would release the necessary application program interface code to the developer.
It would seem natural to conjecture that the openness of the Android operating system could eventually lead to the same kind of market tipping phenomenon that saw the Mac lose out to the PC for business adoption. That said, it isn't clear where the needed network externalities are coming from in this case, since wireless communication technology is pretty standard.
I think you'll find it's more a case of:
"What we fail to learn from history is that we are doomed to repeat it"
"Those who learn from the past learn only that man is doomed to repeat it"
The corollary is:
"Insanity is doing the same thing over and over again but expecting different results."
If the DNA doesn't change, nor does man or what he does.
After millions of years we are only just entering that age in the development of mankind's technology where DNA is going to start changing quite radically.
In terms of Apple, as Umair Haque might observe, if the corporation's DNA hasn't changed, neither will its strategies.
The network externalities will come from app compatibility and data portability, of course, same as they did in the PC vs. Mac case. Particularly, not having to go through iTunes to schlep data around will help with data portability when it comes to Android devices.