Plus EnGadget posted an "internal" AT&T Document that reads "... no subsidies are being offered on the phone at this time." HERE IS THE KEY!!! I don't know how it could be more clear, NO SUBSIDIES at this time, Steve Jobs said that this price point of $499 and $599 was with a 2 year contract thus subsidized. There is the conflict if AT&T now says the $499 and $599 price reflect NO SUBSIDIES.
IMO another hint at possible future subsidies is the fact that the phone is locked to cingular / at&t and you can't take it over as an unlocked phone and stick your tmobile sim card in it or anything. An AT&T / Cingular 2 yr contract subsidy would not lower Apples profits from the phone, only cingulars. Also you must take in to account $500-600 for a phone is a huge cost above other phones for the common consumer in a market where most phones are between Free to $100 with a 2 yr contract.
I would think Cingular is paying apple a ton of money to get exclusive rights for cell service on the iphone, which would mean they will probably have some way of making the iphone more appealing to the average consumer, especially teenagers who are constantly buying ipods and new cellphones. the iphone combines these