This is very spotty at this time but a MacTrast, a site that seems to be on a roll of late, is saying that the next iPhone will also be made available for T-Mobile and can run on its 3G network.
While yesterday's report regarding Sprint getting the iPhone omitted this, it stands to reason that Apple will try to make its iPhones to run on as many networks as possible.
Too bad it's too late for some folks. I've already gone to Verizon and hopefully, I'll be able to grandfather in my unlimited data plan with a LTE iPhone in the future.
Personally, I would like to see Apple make the iPhone 5 available to the pre-paid market as well in addition to the lower end iPhone 4 that will be out in a few weeks.