Well, I have spent considerable time attempting to get ATT to honor their commitment. Their FAQ on the iPhone indicates that existing Cingular customers (that would include former ATT WS customers by their lack of qualification) can keep their existing voice plan, but may be required to add a data plan for $20.
I asked whether Apple would charge the restocking fee since I bought the phone on the basis (in part) that I would not need to surrender my existing plan, and the only way I found out differently was to unpack the phone and actually attempt to activate it. ATT indicated that Apple would charge the fee.
After I cooled down a bit, I called ATT back, and found that the new plan would actually be less than the old plan. So, I'm giving it a try.
That being said, I really do hope that someone files a class action lawsuit against ATT for misleading advertising.
Mike