It's widely assumed that ATT's exclusivity contract runs through at least this summer.
We don't know if the contract included other devices. And we don't know if it forbids even talking to (or about) any other carrier in advance of its end.
So we shouldn't automatically expect Apple to approach other carriers yet on the iPad, or talk about any other carrier's phone.
The iPad stunt says otherwise, seems like it's more than 2010 at this point, so keep hopping. We don't have too know other devices are not included, that breakthrough deal Steve made had to have some sort of catch.
In this case, I am betting AT&T agreed to those prices if Apple gave them more iPhone exclusivity.