I dont mean to threadjack but I am in this same situation. My verizon contract is up in december. Should I just pay the etf ($90 or something) and get the new iphone?
I swallowed the EFT and ported my number over to get grandfathered in on the unlimited data and the iPhone 4. This was back before the WWDC even began and the new phone was announced. Now that I did, looking back I am glad to have done so.
If you are going to wait 6 months then I'd wait a year for the iPhone 5. If you get an iPhone in Dec then you are going to be bummed when all the iPhone 5 rumors start popping up in January.
The only reason not to go w/ ATT is that service in your area is weak. I know SF has issue, as does NYC. But other areas like DC and Atlanta have great service. So it really depends on where you live.