Apple only recently started selling the unlocked iPhone 4, but that hasn’t stopped people from unlocking their handsets sooner, as we know. Of course it will only increase now that Apple is selling the handset unlocked.
Right now, there is no official T-Mobile iPhone, but spokespersons for the carrier recently said that they have over 1 million iPhones on their network (via 9to5Mac) When asked to clarify, they did specify that some of those were unlocked prior to the official unlocked iPhone 4. Still, it definitely seems that this would help pick that up.
What’s more interesting is when you consider that T-Mo doesn’t offer a MicroSIM for phones on their network. This means that users literally have to cut their T-Mobile SIM to fit the iPhone 4. They said that a significant amount of people had “taken the scissors” to their SIM cards.
Just shows that there is demand for it on other carriers.