"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
Apple Seeds First Beta of iOS 10.3.3 to Developers
Registered developers can download the first iOS 10.3.3 beta from Apple’s Developer Center or over-the-air once the proper configuration profile is installed.
We don’t yet know what’s included in iOS 10.3.3, but with a 10.x.x version number, it’s likely to be another minor update that focuses on bug fixes and security improvements rather than outward-facing changes. If anything notable is found in the beta, we’ll update this post.
iOS 10.3.3 may be one of the last updates we see to iOS 10, as Apple is starting to shift focus to iOS 11. iOS 11 will be introduced at the upcoming Worldwide Developers Conference, which kicks off on June 5. The update will be in testing for several months before seeing a fall public release.