Preview at WWDC likely in June, followed by September launch.
Early iOS 11 Videos Appear to Depict Prototype Control Center and App Switcher Gestures
According to Rambo, the files were created in May, suggesting they depict iOS 11 iPhone functionality that was scrapped rather than functionality that has not yet been implemented, but there's technically no way to tell.
In the first 13 second video, the Lock screen is demonstrated. The implementation of the Lock screen is similar the current iOS 11 implementation, but there are small changes.
This is interesting pic.twitter.com/X4GLiMy1c5— Guilherme Rambo (@_inside) August 21, 2017
The second video shows a different implementation of the App Switcher. Instead of double tapping on the Home button, the App Switcher is accessed through a swipe upwards on the Home screen, the gesture used for Control Center. Control Center remains accessible as an app at the right side of the screen, though.
This is also interesting pic.twitter.com/JdYDhZDkev— Guilherme Rambo (@_inside) August 21, 2017
It's possible Apple originally planned to mimic the iPad App Switcher functionality on the iPhone, but later decided against it for a more familiar set of gestures. It's also possible, though, that the videos offer up a look at how iOS 11 will work once the iPhone 8 is released, since it has no Home button.
If there are any significant changes to the way iOS 11 is used on the upcoming iPhone 8, we'll know soon enough. We're expecting Apple to introduce the new iPhone in September, and if past event dates are any indication, we have just two to three weeks to wait.