iOS 6. It brings Facebook integration, Passbook (an app that hold all sorts of passes), enhancements to Siri (as well as bringing it to the new iPad), Maps with turn-by-turn navigation (an in-house app by Apple) with Flyover (3D rendition of cities), improvements to Safari, FaceTime, Phone, and a whole suite of new improvements, like UI tweaks, all detailed at Apple’s iOS 6 page. The update is coming this fall, with a dev preview available to theiPhone 4S, iPhone 4, iPhone 3GS, 4th generation iPod touch, the latest iPad and iPad 2 (no original iPad seen here).
Best of all, the iOS 6 update shows that Apple is willing to mix things up (e.g. the in house Maps or tweaks to the UI), so it keeps promise of more exciting things in the future.