I ordered 2 seperate phones for a new family plan this morning through ATT. The $30 unlimited messaging is shared between the phones on the family plan and it is unlimited messaging to anyone, not just between phones.
Someone here just said Apple fixed thier price issue. A few days ago I attempted a mock purchase on Apple and the pricing for a family plan was off. The apple online people told me, at that time, they did not support a family plan purchase through the apple website. I kept arguing it was there, until they said, yeah but when you finish it tells you to go to the store. So perhaps Apple fixed that issue according to the above poster.
In either case, I was ordering with the ATT premiere to get the wife's discount and it went through without issue this morning.