This information may be percolating up in various threads, but I think it warrants extra attention. AT&T is advising customers to quit retrying. According to this information every time you try again you're placed at the end of the line.
What we have been told by Apple is that every time the activation process is tried again, the phone number is being put at the bottom of the list like it was the first time the activation was done.
They have advised to have customers stop sending the activation through again and give time.
We know for the AT&T side, it is a 10-15 minute delay. As far as how long it is taking for Apple's activation, we do not have that information.
We just got an update.
There is a 1-2 hour delay. *Please leave the phone on and not send the activation through.