Straight from ATT
http://www.facebook.com/ATT?v=app_7146470109
Q: "Does this change only apply to iPhone 3G customers who spend $99 per line or more per month?
A: In most cases, yes. iPhone customers who spend more than $99 a month per line with us generally are eligible for an upgrade between 12 and 18 months. In general, the more a customer spends with us, the less time they have to wait to get another new device. "
Q: What about customers who bought in July, August or September 2008 but don’t spend over $99 a month per line?
A: We value the business of all our customers. The majority of iPhone 3G customers received a significant discount on their device in return for a two-year service commitment during which time we recoup the device subsidy. Getting a new subsidized device is based on several factors including monthly recurring charges and having an account in good financial standing. In general, the more you spend with us, the less time you have to wait to get another device. This is a very fair system. That said, we do offer early upgrade pricing only for iPhone for those customers who don’t want to wait.
In most cases? What are some cases where it would not apply? I hope the press jumps all over them for this. They release this nonsensical upgrade option and can't give a straight answer to their customer base. This whole thing was pure fluff in an attempt to get some positive press for once. I hope it blows up in their face.