Apple will introduce new versions of iOS and OS X at its annual developer's conference.
App Store and iTunes Experiencing Issues for Many Users Worldwide
The issues began shortly before 7:00 a.m. Pacific and appear to be widespread, affecting customers in the United States, Canada, Europe, and elsewhere, according to social media posts. Apple TV services and Apple's Volume Purchase Program are also affected by the service issues.
Update (9:10 a.m. Pacific): Apple's System Status page shows that the App Store, iTunes, and other iCloud services have been restored.