Preview at WWDC likely in June, followed by September launch.
iOS 10 Now Installed on 76% of Active iOS Devices
iOS installation rates have grown significantly over the holiday period, jumping up 13 percentage points between the end of November and the beginning of January. On November 27, 2016, iOS 10 was installed on 63 percent of devices.
18 percent of devices continue to run iOS 9, and six percent of devices are running iOS 8 or earlier.
iOS 10 adoption rates may have seen a jump thanks to the release of iOS 10.2 on December 12. iOS 10.2 introduced several new features, including a new "TV" app, new emoji, improvements to Live Photos, and a huge list of bug fixes.
Around this time last year, iOS 9 was installed on 75 percent of active devices, so iOS 10 adoption rates have eclipsed iOS 9 adoption rates during the same time frame in 2016.
Apple has been steadily releasing updates to iOS 10, and rumors suggest we will see the first beta of the next major update, iOS 10.3, on January 10.