I just called AT&T and they gave me a rundown. The phone must:
1. Have been purchased through AT&T
2. Not be stolen
3. Have its 2 year contract fulfilled
4. BE ACTIVE ON YOUR ACCOUNT
The last one is the kicker and something NO news service has reported on up until now. It has to have its own line on your current bill and 'be active'. I asked 3 times what 'be active' meant, and the best they could explain was that it must have service and 'have been used' (i.e. phone calls made/accepted on it).
I asked if I could add it as a line, and she said yes: $36 activation fee, plus $9.99 per month, and then you have to use it. Then they can unlock it. There's no contract minimum time limit that you have to fulfill to do this (I was told...I was transferred to their activation department which was closed today, so I don't have more details), so as best as I can assume - set it up, use it for a couple of days, make sure your bill is paid, then ask for an unlock, and cancel the line.
There's definitely more than AT&T has told all the news outlets, and you have to call to get the details. Surprise, surprise - AT&T not totally forthcoming? Who knew...