Don't count on ATT or Verizon getting much inventory.
When 4S came out they didn't have more than a few hours of inventory so why would things change for this launch.
This was dependent on the area you live in. My local AT&T store still had one 16GB 4S and a 64GB 4S in stock at 4pm on launch day last year. They told me they got a truck load of them in and that is why they still had 2 left in stock at that time of day.