I would think there is no value to AT&T allowing early upgrades at this point. If they suddenly decided on Friday to move people's upgrade dates up, the chances of getting your hands on a phone that day would be slim to none. If you ordered, it would likely be 2-3 weeks anyway, and people would complain about that, especially the people who bit the bullet and paid the early upgrade price for the phone.

It's far less grief to them to stick to the the policy they already started. Changing their minds now would just cause much, much more grief than they've already gotten.

If someone believes that it's cheaper to swap over to Verizon, and you'll get an iPhone earlier, that their service is better, and that they'll treat you better when the iPhone 5 comes out (very likely much earlier than end the 2-year contract you're signing up for), then they should go.