It's rumored that Apple my look to Qualcomm to build the chip for their iPhone 5.
As CultofMac reports, a company's choice of baseband chips normally hints at what carriers they plan to support. Going with Qualcomm may indicate a choice to open the iPhone to other carriers other than ATT.
That we know of, Qualcomm is the only company that makes GSM/CDMA chips, so it may not be as if Apple has a choice.
CultofMac does bring up another interesting point. Back when Intel picked up Infineon (the previos iPhone chipmaker) Steve Jobs "did not object," and they suspect that it may be even more indication of Apple's plans for a CDMA iPhone.