If Clearwire can upgrade its network form WiMax to TDD LTE (85% similar technology) as scheduled and China Mobile (650 million Subs) finalizes a deal with Apple while completing their TDD LTE network, then Sprint will have a game changing world iPhone capable of roaming from FDD to TDD LTE.
On another note one should consider the game changing aspects of a dual mode FDD and TDD LTE radio chip, which is expected to be on a future iteration of the iPhone in 2013.
The LTE standard supports FDD (Frequency Division Duplexing) mode adopted by DOCOMO and TDD (Time Division Duplexing) mode expected to be adopted for LTE networks in China and other markets, which will help to further the development of advanced mobile devices by manufacturers worldwide.