I assume that whatever AT&T's website says is the most current. I don't think anyone here would have information that is more current than AT&T themselves.
That aside, I just created a dummy order for a black 16 GB iPhone 5 and the shipping estimate was shown as follows:
Your iPhone 5 16GB will be shipped in 14-21 business days
I just returned from AT&T. They've got them I'm stock. I went with my cousin, he bought two. One for the wife, and one for him. No crowds, no lines, already an AT&T customer, we were outta there in just 30 minutes.
Just got back from the ATT store and they told us that it is a 3 to 4 week wait time. They also told me that some people got theirs in a little over a week after pre-ordering them.