They'll remain competitive by the technology they use, and that alone. I don't like CDMA/EV-DO technology due to the limitations which is why I stay with AT&T. I'll take the data throttling over EV-DO any day. My dad has the Verizon iPhone 4 and at home it displays an 'o' where mine shows 3G or now 4G with AT&T. I pull about 5mbps where he gets like 0.01 down. Its always been like this. With the cell tower in site he can pull 2Mbps on a good day and I can pull 8mbps.
I love being able to use voice and data simultaneously. Now when the LTE iPhone hits Verizon will win hands down when it comes to coverage but AT&T will still have the advantage. They'll have UMTS/HSDPA/HSPA+ to fall back on when not using LTE. With Verizon and Sprint its only EV-DO or LTE. That's going to be a hard transition for some people.
I love being able to use voice and data simultaneously. Now when the LTE iPhone hits Verizon will win hands down when it comes to coverage but AT&T will still have the advantage. They'll have UMTS/HSDPA/HSPA+ to fall back on when not using LTE. With Verizon and Sprint its only EV-DO or LTE. That's going to be a hard transition for some people.