The iPhone had overwhelming dominance in the consumer smartphone space. That is absolutely without question. That dominance is how it moved into the enterprise market, the gaming market, and so on. Exactly how Windows invaded the server room based upon the massive dominance it had outside of the server room.
If Google didn't have their huge amounts of cash, we'd still have the Blackberry OS, which is still enormously successful (though it's taken a hit recently), and we'd have Windows Phone 7, which is actually a really damn decent operating system.
If Android didn't prevent absolute iPhone dominance, RIM would be dead in the consumer space (and dying in the enterprise space), and Windows Phone 7 would have been DoA. Every single review would say "it's cute and all, but without the apps its a nonstarter".