Okay, that was beyond what a reasonable consumer would expect.
Yesterday, I came home to discover no box at my doorstep, a box that should have contained my DLS modem. So I called AT&T to find out what happened.
Turns out, AT&T did not process my order last Tuesday, when I called it in, and it only got entered this Monday, full 6 days later! On top of that, the order did not contain the DSL router. I was glad I called.
The customer service agent added the hardware to the order and confirmed that it will arrive on or before the day that my service will be activated--next Monday!