Same here but from sprintAT&T just sent me an email thanking me for choosing AT&T. In the past when I have received these types of emails, the phone ships out very soon. I'm assuming this likely means an AT&T SIM card has been installed and/or linked to a device with my account info.
Happy times!
EDIT::::: I ordered through the Apple Store App at 3:10am EDT on 9/12 with delivery slated for 9/25.