"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
Apple Seeds Fifth iOS 9.1 Beta to Developers and Public Beta Testers
The new iOS 9.1 beta, build 13B137 (13B5137 for public testers), is available as an over-the-air update and through Apple's Developer Center. There's a second build, 13B139 (13B5139 for public testers), that's unique to the newly released iPhone 6s and 6s Plus.
iOS 9.1 offers new features and compatibility updates for upcoming Apple products like the new fourth-generation Apple TV and the 12.9-inch iPad Pro. The iPad Pro ships with two accessories, the Smart Keyboard and the Apple Pencil, both of which are deeply integrated into the operating system.
The update includes Unicode 8, adding support for emoji like the taco, burrito, cheese wedge, middle finger, unicorn head, and more, along with a new Messages option in the Settings app, allowing users to disable photos for their contacts.
It is not yet known when iOS 9.1 will be released to the public, but it's likely it will come in late October, coinciding with the launch of the new Apple TV. iOS 9.1 is required for setting up the new Apple TV through an iOS device.