I am not sure the Windows precedent applies here. At the height of the reign of Windows the landscape as far as the competition goes was extremely different. To point out one of the many contrasts - Apple did not have the kind of money it has today or the strong auxiliary channels: apps, music, ebooks etc to support its main product line.

I don't think anyone can say the world is going to be 90% Android or 90% iOS as far as handhelds are concerned. It is a market that is still opening up and there are at least three distinct pricing segments in it. Plenty of space for the top 2-3 to grow without killing anyone else.

Except iOS and Android have the exact same format - large touch screen. The technical differences won't be relevant to 99% of customers, it's the advertising and brand recognition that will make the difference.

By that token, VHS and Betamax both had the "exact same format" of magnetic tape in plastic boxes. Their similarities didn't stop one from driving the other out of the consumer market.

Personally, I suspect that Apple has lots of time before Android chokes off the smartphone market, and even longer in the tablet space. But eventually, the commodity-hardware producers are going to do to those devices what Compaq et al did for PCs; Apple will have to decide between marketshare and margin, and I suspect they'll choose margin even if it makes them decreasingly relevant. But by that point maybe they can invent some new niche.