Attention existing At&t customers. If you recently purchased a phone from At&t they may not be willing to let you have the iPhone at its lower price upon release.
According to TUAW:
If you are a current AT&T customer and you do NOT have a 2G iPhone
You may or may not be eligible to buy the iPhone 3G at its lower price upon release. It depends on the length of your contract, the time of your last handset upgrade and anything else that weighs into AT&T’s standard upgrade policy. The pricing for non-qualified upgrades has not been determined, but phones will still need to be activated in-store and with a data-plan and two-year contract.
My guess is the amount of time is being left vague to see just how bad the backlash is before committing to a time – so if you’re an existing At&t customer now might be the time to let your voice be heard.