I'm not sure what lesson you drew from the Amiga (which was definitely killed by bad [un]management, not because it was closed (which it wasn't) or even overly expensive), but I agree with the general sentiment that Open (which currently equals Android) will win in the long run. It will win on price and volume and being "good enough". Here's an interesting graph ("The Rise and Fall of Personal Computing") which I have not verified in any way. Look at the slope of android vs the apple products. That to me says "android will win in a couple of years".
This assumes that Apple will continue to be AAPL and position themselves as selling exclusive high-end products, meaning they'll try to keep margins very high while refusing to play in some markets on pure principle (like the 7" tablet form which IIRC Jobs didn't want)
What we can expect is ever more litigation from AAPL as the balance of power starts shifting. Perhaps in two years we'll have have a more or less clean split between ios android and win8. In the end though, the march of Commoditization is relentless, and it favors cheap-and-open, neither of which describes MS and Apple.
I've actually been thinking that the phone form factor as we know it today may well go the way of the dodo in the future. Who really makes calls any more? Maybe that Galaxy Note is a transitional form to a bigger device ("tablet") which CAN make calls but is really optimized for reading/dictating. Heck, in the future what's to say that your speech won't be recognized into text or phonemes from text AND speech alike, burst over an IP channel and then synthezied -- possibly in "your voice" -- on the other end. But I digress.