CDMA Verizon iPhone 4 contains GSM chip
Universal connectivity for iPhone 5?
The Verizon iPhone 4 contains a radio chip capable of connecting to both CDMA and to GSM networks, a detailed autopsy of the device has revealed.
Naturally, the Veriphone's integrated aerial is tuned to CDMA, but there's technically nothing to stop Apple incorporating a second, GSM-tuned antenna too, allowing it to produce a single handset capable of connecting to either network.
Or it will simply unify the circuitboard, which will be plugged into different casings for CDMA and GSM operators.
IFixit's teardown reveals that most of the Verizon iPhone's parts are not interchangeable with those from a GSM iPhone 4.
With no Sim slot in the handset, Apple has labelled the phone "does not contain any user-serviceable parts", and there is a pair of its 'pentalobe' screws  to keep the case shut. ®