Do customers care who is carrying their cellular signal?

There is no reason to think that Apple would have to stick with AT&T or Verizon. Apple could crank a mixed CDMA and GSM phone. That would free Apple to license chunks of bandwidth from both Verizon and AT&T. If those companies can't come through with the necessary bandwidth Sprint could always be added to the mix. The names aren't really important, the important thing is that Apple could buy up the necessary bandwidth to keep users happy. via Why Do iPhone Users Have to Put Up with Carriers? - AppleMatters.

Verizon sold out the iPhone within 17 hours. All those who ordered the Verizon iPhone are most likely people for whom the network mattered.

Paul Hontz on why CDMA data/voice limitations are "not a big deal".

As long as you are connected to Wi-Fi, you can be on a call and still use data. At home I have Wi-Fi, at my office I have Wi-Fi, nearly every restaurant downtown has Wi-Fi. The point is Wi-Fi is ubiquitous. via Codesketch

Paul has a point. It’s not a big deal to have a smart phone with a hotspot feature if you use that feature very little or not at all. But then why pay for a data plan? Just get an iPod Touch and use one of those free regular phones to make calls.