MacRumors didn't copy the entire sentence from AppleInsider:
"Customers subscribing to a new AT&T FamilyTalk plan will need to purchase at least two iPhone 3Gs with the plan, unless a first-generation iPhone is already owned by one of the family members that will be using the plan. In that case, the new phone is sold and activated and the old iPhone is ported over to the new plan."
Actually, everything I've read about the ATT store says only one per person. I was planning on buying 2, one for the wife and one for myself as we already have the FamilyTalk plan. If I upgrade to the family talk plan, I would gladly pay for two iPhones.