I have not. I have waited outside (once...never again) the At&T store near me for the iPhone.
I know they have their one-to-one training early in the morning before store opening during the weekdays and on weekends. I'm pretty sure the early classes start at 7 to 7:30ish AM.
I'm sure you can hang out near the Ramp/Sears pick-up area entrance to the Mall all night if you choose.🙂