If it is lte, it will work on both att and vzw network. Here is the big problem. Att and VZW work at 700mhz, wimax works at 2.5ghz. The higher the frequency, typically, the higher the throughput/lower the penetration. What it takes for at 700mhz to hit 50mbps/20mhz, takes 2.5ghz, about 10mhz. My point is, apple will not release any 4g phone unless it is 100% up and stable, they did this for 3g. Right now, I can nail about 125mbps with wimax, about 100mbps with lte, in the lab. In real world testing, I can nail them both at 50mbps before exceeding bandwidth of the internet server. Yes, I can pull information quicker then the internet can give it. With wimax, I can hit 99mbps, hitting my own server, in real world tests. I can also hit my own server at 91mbps with lte. BUT ONLY using the 2.5ghz frequency. Verizon will be using the 700mhz spectrum so it will need to increase radio frequency, to increase throughput. But this will also limit the number of people using the network. What really needs to happen is a dynamic system in which the right technology matches the right need. Which will happen right after we have a good buildout, and egos get replaced by the need for money. Once that happens apple will then get on the 4g bandwagon, which means you have many years.