"Facebook integration is big -- it's going to make a lot of people very happy -- and I think that Passbook could become very important down the road, as a way to handle all the different virtual slips of paper, not just tickets and boarding passes, that people have on their iPhones and iPads embedded in their apps."

A beta of iOS 6 is available today for developers only, and the upgrade will support iPhone 3GS and later, the second- and third-generation iPads, and the fourth-generation iPod Touch.

Apple was coy about the release date, saying only that it would be available this fall. As it did last year, Apple is expected to launch iOS 6 alongside a new iPhone, perhaps as early as September, but failing that, in October as it did with the iPhone 4S last year.

Not surprisingly, Apple made no mention of a next iPhone, just as it kept quiet last year about a new handset.

Cook, who opened and closed the keynote, did not spend much time on stage, essentially mimicking former CEO , his second-to-last public appearance.