As we might have suspected prior to todays iPhone event out in Cupertino, the Gold Master (GM) build of iOS 7 is now available for developers to download. This comes ahead of the public release of iOS 7 on September 18.
Registered iOS developers should head into the Apple Developer Center where you should find a full copy ready and waiting for you.
Update: No OTA, sorry folks. Little carried away with the typing. Developer center only.