Now that everyone realizes that you need a 2 year contract with AT&T to get the new iPhone and it will be extremely difficult for current AT&T/Cingular customers to get it, the complaints have already started. See this post from Om Malik at GigaOM called No Contract, No iPhone for You.
Simple reason you see. AT&T makes less money when an existing customer gets the phone. They don't get new revenue on the books. Sure there is a retention play, but that is hard to prove the value of it. Sounds ridiculous I know, but the quant-jocks at AT&T assume that x% will leave anyway and in order for a retention play to work, it needs to significantly lower the amount of people that would have left anyway. That my friends is called a Save Rate and it is hard to prove out significantly.
Hate to see it, but this was my prediction for the iPhone. Apple wins BIG and AT&T takes it on the chin with upset current customers, service issues, and of course that network of theirs will cause people headaches. I'll sit on the sidelines with my Verizon Treo and wait for the iPhone or a copycat version and use it on Verizon's great network.