The pricing scheme is as follows (and remember, I am typing this, from my computer at work at an ATT Corporate store, while staring at the email as follows from apple!!)
I can tell you in advance, this is not going to fit what EVERYONE has been told because there are reps on customer support who probably STILL dont know there is a new iphone, but for the majority of the public, it should be:
If you have a 2g iPhone, and never upgraded, the phone will be either 199 or 299 (depending on whether you wanted 16gb or 32gb).
If you have a 3g iPhone and you have had it for MORE than 6 months, it will be 399 or 499 (again, depending on the model)
If you have a 3g and have had it for less than 6 months, but more than 30 days, it will be 599 or 699.
And if you have had the 3g for less than 30 days, you can return it to a corporate store or apple store, and pay the 10% restocking fee, and swap for whichever one you want.
This is the official memo from AT&T and Apple.