Mike- I think the bulk of iphone contracts are ongoing ( as in laddered), not to be continued for another two years. Only those people who just renewed with that requirement plus new customer base would be in that 2 year from now wait.
As a Verizon user, I don't think the switch to Verizon will be as happy as many believe, only because they do not travel. The real advantage of Verizon is if you are traveling all over the country. Even around the world, Verizon as ways to keep your business. While I'm not worried when LTE hits, I do worry about the 3G service becoming over taxed with an influx of iphone business. Currently I find my 3G service adequately fast to do Sling and track about 50 stocks and poll my POP e-mail accounts without problems. If Iphone hits I may see that service get throttled back.