WWDC 2013: iOS 7 Beta is Now Available for Developers to Download.

Now, Apple has posted the first beta of iOS 7 for developers to download, with 11A4372q as a build number. The firmware is
available for the iPhone 5 (Model A1428), iPhone 5 (Model A1429), iPhone 4S, iPhone 4 (GSM Rev A), iPhone 4 (GSM), iPhone 4 (CDMA), iPod touch (5th generation).

You can download the beta here!