The upcoming iPhone 5 will almost certainly be a single phone that supports multiple networks, namely CDMA (such as the one used by Verizon or Sprint in the United States) as well as GSM(which is used by AT&T and T-Mobile in the U.S.).
This has been rumored before, and even at one point half confirmed by a Verizon executive, but nothing like some good old evidence from the field to turn a rumor into a near-certainty.
I was recently approached by a developer of some of the most popular apps on the iOS platform today, who asked not to be named and offered solid proof that supports the above claim.
Read more: Source: The iPhone 5 Will Indeed Be A Dual-Mode CDMA / GSM ‘World Phone’