"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
Apple Seeds Fourth iOS 9.2 Beta to Developers and Public Beta Testers
The fourth beta of iOS 9.2, build 13C5075, is available as an over-the-air update and through the Apple Developer Center. Public beta testers can download the update over the air. Apple has also released Xcode 7.2 beta 4.
Earlier betas of iOS 9.2 included changes to the Safari View Controller, which is what allows a pop-up Safari window to be used in third-party apps. In iOS 9.2, Safari View Controller supports third-party Action Extensions, letting apps like 1Password to be accessed in the Safari view of other apps like Tweetbot.
Safari View Controller has also been updated with the ability to long tap on the Reload button to reload content without content blockers and it now supports the request desktop site function. The second iOS 9.2 beta improved Safari View Controller further, introducing support for dismissing it with an edge swipe.
Along with improvements to Safari View Controller, iOS 9.2 also introduces Arabic support for Siri, support for AT&T's NumberSync Wi-Fi Calling feature and it includes bug fixes for iCloud Keychain, Apple Watch syncing and pairing, audio quality when streaming to stereo systems, and more.