This matchup you envision has already been played out in markets other than the US. Android still won. Why is it always this "wait till" expectation with for some when it comes to the iPhone versus Android marketshare? The results always remain the same. Android wins.
Agreed, getting iOS on Sprint and T Mobile at the launch of new hardware(and Verizon getting the same) should help sales( and in 07/08 would likely have gotten Apple's market share to an even larger amount, controlling a mass amount in the US for a time), But the ability of Android to scale across hardware designs of all types means it will win out. That's the reason Windows won out in the 70s and 80s, it's the design of Apple's business model that allows it(which isn't a bad thing, as I think iOS would suffer if Apple built it with HTC, Samsung, LG, etc in mind)
Never will one hardware company be able to control a market(unless perhaps they create it or get in very early, but even then if other big players push hard enough, they can break in....look at the MP3 player market, Apple won that battle, but other companies slowly chipped away and that wasn't nearly as important as tablets/smartphones IMO.)
Smartphones are the forefront of computing now, every one in the desktop business wants to make sure they get a piece of the market that their sales are going, which is tablets and smartphones.
And so Apple will create a great product with an approach that works better in my mind, but Android is quite good and will be able partner with more big players and out sell Apple. Same with MS, I could see them out selling Apple, at least with Nokia on board(even if they only get some of their old market, they will still be a major player)
But that doesn't mean Apple's one device isn't the best fit for many people.
My interest is in HP, a huge hardware player bought a great software product(and the people to keep improving it)...if they play their cards right, I hope to see them take off. Putting WebOS on all their PCs seems like a great move, sure some people might not use it, but as long as it's done so it's not annoying to those who want to avoid it, it has they chance to introduce people so come time to get a new smartphone or tablet, they have experience with WebOS and are that much more likely to jump on board.