I knew about the exclusivity, that wasn't a huge deal. (When I first signed on; as AT&T's service at my house got progressively worse, it has become obnoxious.)
What torques me off is AT&T's locking my new Family Lines into a 2-year agreement, when I added already-owned phones to it. When I upgraded to the 3G, I added my old original iPhone as a second line for my wife; they made that line, a customer-owned device that wasn't subsidized in the first place, a 2-year contract; with ZERO early upgrade ability. So, even though it was already my phone, bought unsubsidized, when it broke six months later, I couldn't upgrade to a new phone cheaply. Same with the bought-from-a-friend-who-upgraded-to-3G phone we added for my kid.
Went from one line at $60/month to three lines at $180/month, with the second and third lines being "customer-owned" phones that never had a subsidy, and they made all three 2-year contracts.
Of course, we only found this out after my wife broke her phone, and we went to upgrade her to the 3G, which AT&T had refurbished for $99. They said "nope - $499 please." After yelling at a couple billing managers, they agreed to sell it to us for $99, asserting that the 2-year contract on the extra lines was an error. (Of course, buying the 3G at the discount put her line on a brand new 2-year contract.) Then, a year later, my kid's original iPhone started misbehaving, and we went to upgrade it. Nope. Not eligible. This time, I didn't even bother arguing with a manager. The moment my wife's part of the AT&T contract expires (next January,) we're dumping AT&T.
For Verizon if Apple has released the iPhone on Vz yet, otherwise we're unlocking and moving our phones to T-Mobile. I'm sick of AT&T's bullcrap.
(Funny, we left T-Mob when the iPhone came out because AT&T had better signal at our house - meaning they HAD signal at our house. Now, T-Mobile has a perfect signal at our house, while AT&T sucks.)