Today, Apple released a new round of developer betas, although not for its major updates that are coming in September. Instead, the third builds of iOS 10.3.3, macOS 10.12.6 Sierra, watchOS 3.2.3, and tvOS 10.2.2 are now available. It's the first new builds for those updates in two weeks.
As the version numbers indicate, there are no new front-facing features in any of these updates. Instead, they focus on bug fixes and stability improvements. Also, the release notes don't say anything particularly enlightening, and nothing that wasn't there two weeks ago.
All of the big news features will be coming this fall, when Apple released iOS 11, macOS 10.13 High Sierra, watchOS 4, and tvOS 11. iOS 11 is the most significant update of the bunch, with a number of improvements for the iPad, built-in screen recording, a Files app, drag and drop, a screenshot editor, and more.
Since the major updates are the ones that are coming from Apple's development pipeline, it really shouldn't be too long before the general public sees these minor updates.