Preview at WWDC likely in June, followed by September launch.
Apple's App Store Reaches 25 Billion Downloads, Now on Pace for 15 Billion Apps Per Year
The App Store took a little under two and half years to reach 10 billion downloads, and less than six additional months to reach 15 billion downloads.
With today's milestone, the App Store has seen its last 10 billion downloads come over a period of just eight months, putting Apple's pace at 15 billion downloads per year and undoubtedly continuing to accelerate. As tracked by our sister site AppShopper, Apple has approved a total of nearly three quarters of a million apps for the App Store, with over 550,000 of them currently available in the store.