MG Siegler has a fascinating post at TechCrunch about Android and iPhone. He poses the question about whether Android would have been as successful as it is if it wasn't for the AT&T exclusivity deal. This is going to be a short post that talks about some facts that I think speak to the fact that Android is successful on it's own, not just because Apple is "letting it".
Despite the superior user experience of the iPhone (if you say Android is better in this department, I would seriously question that, having owned two Android devices and an iPhone), Android has somehow gained a lot of momentum. I suggest it's not because iPhone is only available on AT&T.
1) To see what it would be like if iPhone was available on every wireless network, you don't need to look far. Canada has a strong Android presence despite every carrier selling the iPhone.
2) Apple strong arms everyone -- including wireless retailers. The only reason iPhone's sell at all is because users demand them. Your local wireless retailer will try and sell you anything other than an iPhone if at all possible -- and that usually means Android. Why? Because the commission retailers make off iPhones is next to nothing compared to what they make from other devices.
3) In Canada, wireless retailers hate that Apple stocks their Apple stores before them. When the iPhone 4 was launched, retailers got their (small) initial allotment of phones from Apple, and then nothing for a month. All they got were a bunch of grumpy customers looking for iPhone. This reinforces the bitter taste in their mouth towards Apple, and makes Android the preferred device to push.
4) People looking to switch away from Blackberry feel more comfortable on Android. iPhone feels really locked down compared to Android -- and the flexibility is something Blackberry users love. Go to any wireless retail store, and ask what device they are using. A year ago, it would have been Blackberries on their hip -- today it's often a Motorola Droid, and they love it. Guess what they are more likely to sell if asked by a customer for advice?
With all of this said, I think there is room for at least two successful platforms -- and it's currently iPhone and Android. Even if iPhone was available on every carrier in the US, I suspect Android would still have been successful -- perhaps not AS successful AS fast, but certainly nothing to shake a stick at.