"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
Apple Releases iOS 5 with Notification Center, iMessage, Twitter, and More
iOS 5 brings more than 200 new features, including Notification Center, iMessage, Newsstand, Reminders, and systemwide Twitter integration.
iOS 5 is compatible with the iPad 2, original iPad, iPhone 4, iPhone 3GS, and third- and fourth-generation iPod touch. It will also ship on the iPhone 4S, which launches on Friday. An iOS 5-based version of the Apple TV software, labeled software version 4.4, is also available.