Don't believe the spin about this being "good" for at&t customers. This is all about what is good for at&t. But hey that's business, and I don't mind that at all. At&t wants to make a profit like any other business, but I do get annoyed by the spin.
If at&t wants to improve their network and get better set up for the future, they can either take their profit hits now and develop the network, or raise the costs to consumers. Trust me, at&t is expecting people's data usage to increase over the next several years, and they are banking on the idea that many people will opt for cheaper plans and then pay overage costs. It makes no sense for consumers to try and decrease their data usage while the newer phones are all about consuming data.