ios7 is ready for developpers
A simple Message from Apple:
Reimagine your apps on iOS 7. Download the SDK and start exploring new multitasking APIs, dynamic motion controls in UIKit, Air Drop, Sprite Kit, enhanced video APIs, new features in Game Center and Map Kit, and so much more.
iOS 7 beta and Xcode 5 Developer Preview are now available in the iOS Dev Center.
read here how to install the beta http://www.iphonehacks.com/2013/06/install-ios-7-beta.html