While the iOS 7 Gold Master (GM) released on September 10 should be binary-identical to the General Availability (GA) version released today, September 18, some people seem to want the comfort of getting what everyone else in the world is getting. If you're one of them, or if you're stuck on the beta and aren't sure how to get off, here's what you need to do to switch to the official release version:
If iTunes says there's no newer version to update to, you can force the issue by putting your iPhone, iPad, or iPod touch into DFU mode after the backup, then doing the restore. DFU (Device Firmware Update) mode will make sure you download and install the latest release version of iOS off of Apple's servers.
If you have any questions, or have any clever tips to share with us, leave them below!