July 8 will mark the release of the next beta of iOS 7, according to "trusted sources" that leaked information to BGR. That date will see the build released to carriers for testing, and the beta will reportedly be released to developers on the same day.
Apple typically delivers beta builds of iOS 7 on Mondays, as was the case with the second beta released this week. Should the third beta iteration materialize on July 8, it would be doing so roughly a week ahead of when iOS 6 beta 3 appeared. That build was released on July 16, 2012.
The most recent beta brought support for Apple's iPad, so the new build will likely be available for all compatible iOS devices at the time of its release, including the iPhone, iPad, iPod touch, and Apple TV. Reports hold that Apple has focused on refining iOS 7's design elements, with the goal of making the experience cohesive across the entirety of iOS.