Yeah, apple will keep gaining share in US but guess who will win in the emerging markets like China, India and Brazil. Microsoft will now start reaping rewards for its years of giving OS for free to these markets (basically by not cracking on piracy).
In these countries, its not about coolness or design. Its about the price.
Want an example? Guess how many iPhones sold in India?
And people do buy Macs here (mostly computer enthusiasts or programmers). You can find many Macs at FOSS conventions (I know, ironic).
Hint: why do you think there's so much outsourcing to India?
The one with the best mobile OS?
Unless Microsoft buys Palm, it's not Microsoft.
Sure iPhones are expensive now - but older ones will start reducing in price for markets like India/China - and the iPhone has very good internationalization support, along with a virtual keyboard that is far better at adapting to languages like Chinese for input.
You speak of long term but you are only looking at iPhone prices today instead of the fundametals.