"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
AirPods and AirPower: Everything We Know
Apple Seeds First Beta of iOS 9.3.3 to Developers
The first iOS 9.3.3 beta, build 13G12, can be downloaded immediately from the Apple Developer Center.
We don't yet know what changes iOS 9.3.3 will bring to iOS 9, but as a minor 9.x.x update, it's unlikely to introduce any major tweaks. There is no iOS 9.3.3 update available for the 9.7-inch iPad Pro, suggesting the new beta does not fix an issue that bricked some 9.7-inch iPad Pro devices. Apple has also pulled the iOS 9.3.2 update for the 9.7-inch iPad Pro and has not re-released it.
The previous update, iOS 9.3.2, introduced support for using Night Shift and Low Power mode simultaneously and fixed a Bluetooth bug that caused iPhone SE devices to experience poor audio when connected to a Bluetooth device.
We will update this post with any changes that are found in the new beta.