Interesting speculation from TheStreet.com…
This makes sense from Apple’s point of view, since T-Mobile uses the same GSM voice transport technology that AT&T uses. Their 3G carrier frequency is different. But, that is a minor issue.
If true, AT&T Wireless will probably throw a huge party if T-Mobile will be the designated U.S. competitor instead of Verizon. Why? There are two reasons:
First, (using subscriber counts from Wikipedia for simplicity), Verizon’s huge customer based of 89 million (TheStreet.com says it is 71 million which could very well be the correct count) compared to T-Mobile’s 34 million gives it a huge advantage in moving iPhone’s into millions of their current customers which might tempt current AT&T customers to give up their GSM iPhonef for a Verizon CDMA iPhone. T-Mobile’s relatively tiny customer base would have less visible and word-of-mouth impact.
Second, and more importantly, T-Mobile’s late-to-the-game 3G network rollout is still in its infancy and provides even worse coverage than AT&T’s. In my area, T-Mobile 3G is only available in a narrow corridor that appears to be less than 20 miles long. It is essentially only available in the metro area. There is no incentive to move from AT&T’s larger 3G network to T-Mobile’s. Verizon, on the other hand, has a huge 3G network that many people would be willing to migrate to.
In other words, a T-Mobile iPhone would have minimal impact on AT&T.