The GSM phones come first because GSM is the world standard (though China and India are changing that rapidly). However, Verizon doesn't mind all that much because the longer development cycle for CDMA versions of the phones means quirks that develop on the GSM phones can be ironed out for the CDMA version. And for the whole "service tanking" thing, Verizon already has a stronger network than AT&T and is expanding. AT&T is counting its money. Verizon is rolling out LTE and the iPhone, assuming it hits, will be LTE-capable. That means the 3G network will shortly start to have less demand placed on it. However, I have the feeling my logic and reason may not be welcome here.