I believe that the phone doesn't have support for the frequencies on which AT&T's GSM network runs, but it does have support for T-Mobile's GSM network. So for now, T-Mobile looks like the only carrier in the US that this will be going to (with Verizon and Sprint both running CDMA and not being able to carry it).

Off-topic, but still: In the US you seriously need some thorough regulation to make this bullshit go away.

You are acting like this is how a normal market is supposed to work. To help you gain some perspective I welcome you, and your standard GSM phone, to any country anywhere in Europe to see how mobile phones, networks and service-providers are really supposed to work in a competitive market.

As an American, I officially envy you, and I've been bitching about the cellphone situation for years. T-Mobile is the closest to European phone practices that you can find this side of the pond.