Apple's iOS 7 beta 5 available for developers; video shows new "slide to power off" design34
The update weighs in at 150MB and includes a seed for Apple TV. An iOS 7 device will be able to set up Apple TV after restoring or resetting all settings. Apple iPhone 4 and the Apple iPad 2 are not supporting this feature. Other changes include a new design for the "slide to power off" function. There are also new "in-call" icons and the install screen on iOS7 beta 5 is the same color as your iPhone. The white iPhone now shows a black apple on a white background (see the slideshow below).
Most likely we will see the final version of the OS roll out around the same time that the next iteration of the iPhone is announced or released. The latest information we have is to expect a September 18th unveiling of the new devices from Apple, with a launch on September 27th.
source: AppleDeveloper (subscription req'd) via 9to5Mac