The new system will be available in the fall.
In opening the keynote, Cook noted that the company's online App Store has served up 50 billion downloads in its five years of existence. He said there are 900,000 apps in the store, 375,000 of which were designed for the iPad.
"Just a few hundred from those other guys," he said, in an apparent swipe at rival tablets that run Google's Android system and others.
He also said the App Store has 575 million accounts, "more accounts with credit cards than any store on the Internet that we're aware of."