I really hope they reduce the price, but it should be noted that they are going into each and every account to remove MMS restrictions.
Source
We were just told the real reason why AT&T wont be supporting MMS on the iPhone 3G or iPhone 3G S at launch, and youre going to laugh Technically it will work right away our ninja tells us. The are no extra plans or higher fees weve just learned (the unlimited $20 package covers unlimited SMS and MMS), and the reason its not good to go right away is because AT&T has to manually remove all the Opt Out MMS codes on each account. Basically, if we were to summarize this, and were going out a little bit of a limb, remove the Opt Out MMS code, and MMS will work with the final OS 3.0 build right away. Who wants to try it with the GM 3.0 build just released?
Source