The new Maps feature, which leaves Google Maps behind, looks fantastic visually and should be more useful than ever with real-time traffic information and incorporated Yelp ratings. Siri made her way to the new iPad and the iPad 2 and will now integrate with a lot of third-party apps like Yelp, OpenTable, and Rotten Tomatoes. Facebook and iOS 5 didn't get along so well, but they've made nice and iOS 6 will see Facebook contact and calendar integration as well as the ability to post status updates from the Notification Center or through Siri. FaceTime should see more, uh, facetime now that users can use the app through their cellular network and not just over Wi-Fi.
That's just a small handful of what's being changed in iOS 6, which is due out in the Fall.