iOS 7 beta 3 due out July 8th
According to inside sources, Apple is looking to keep on a tight schedule and release new beta updates for iOS 7 every two weeks or so. The same sources for BGR were correct in their information on when to expect iOS 7 beta 2, so it seems reasonable that they would have accurate info on iOS 7 beta 3.
That means we should expect iOS 7 beta 3 on July 8th, and it would also mean that Apple would have time to get through approximately approximately 9 beta versions of iOS 7 by the end of September. Unfortunately, there's no word on what kind of improvements and features we should expect in the next beta version of iOS 7, but if the leak is right, we won't have to wait long to find out.