Both Sprint and T-Mobile have 4G...and have HAD 4G for most of last year while Verizon can't even put out a 4G phone apparently; and when it does, it doesn't have a 4G network.
It all boils down to "I have 4G. Do you?" and "I pay 80.00 a month for unlimited EVERYTHING including Nav. Can you?"
Sure, Sprint may switch to LTE in the future, but they're waiting for Verizon to work through the headaches first since they are the first to try it on a scale as large as the United States. In the meantime, we have 4G WiMAX that works quite well, albeit with heavier battery usage. someday VZW customers will see what it's like to have a battery drain really fast.
T-mobile's 4G isn't 4G. Its an evolution of technology that already existed. The only reason they did it was because they couldn't afford an LTE rollout. Sprint's 4G provides speeds that don't remotely qualify as 4G in most areas. WiMax is a dead technology, and everyone knows it. Why do you think Sprint hasn't made any effort to boost speeds?
I'm not quite sure why you're ragging on Verizon here. They went from a first data call in August 2009 to a fully-functioning 4G network in 2010. Thats less than 18 months. That they were able to do it that fast AND have phones in the pipeline to take advantage of it is nothing short of a miracle. I mean, you're talking about a NEW technology on a scale that no one has attempted. When Verizon started building their network the final spec and standard wasn't even APPROVED yet. They couldn't have started building out a network any sooner even if they wanted to.