Preview at WWDC likely in June, followed by September launch.
Apple Releases iOS 9.0.1 With Multiple Bug Fixes
iOS 9.0.1 is available to all iOS 9 users as an over-the-air update.
iOS 9.0.1 is a minor update that introduces bug fixes and performance enhancements to iOS 9. iOS 9 is Apple's latest operating system, which focuses on proactivity and intelligence with updates to Siri and Search. It also includes a split-screen multitasking feature for the iPad and updates to several Apple-branded apps.
Today's iOS 9.0.1 release precedes iOS 9.1, which will mark the first significant update to iOS 9. iOS 9.1 includes new emoji and settings for acclimating the "Hey Siri" activation feature to an individual user's voice.