Earlier today, people were reporting issues downloading media from the iTunes Store.
Orignally, some users were unable to purchase content from the App Store, Mac App Store, and iBookstore. iCloud and iTunes Match services were also seeing problems.
Apple has remedied the issues, updating its System Status page to acknowledge the services returning to full functionality.
Since the fixes, Apple has confirmed new issues for FaceTime users, affecting their ability to make FaceTime calls.