AT&T made its plans to gobble up T-Mobile public back in March. The deal will cost AT&T $39 billion. Sprint is not happy at all about the purchase deal and has been pushing the FCC to block the acquisition, though it seems unlikely that a block will happen. Most suspect that Sprint is simply trying to force some limits on the merged company to make its position stronger in the market. AT&T and Verizon are the only two carriers that official have the iPhone on their networks with Verizon only having the iPhone 4.
With AT&T, looking to gobble up T-Mobile it would be easy to expect the iPhone to come to that network eventually. T-Mobile USA has told 9to5Mac that it already has a huge number of iPhones operating on its network. T-Mo claims that over a million iPhones are on the network already. It says most of the devices are not the iPhone 4. To get the iPhone to operate on the T-Mo network the users have had to cut their normal SIM cards down to Micro-SIMs using scissors.
The surprising part to me is that since the radios inside the iPhone won't operate on the T-Mo network at full capacity, the iPhones users can't get 3G or 4G service. The T-Mo USA rep also noted that Micro-SIMs are in the works but offered no details on release. The tease that there may be a surprise come September was also offered hinting the iPhone might come officially to the network then.