"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
iOS 8 Adoption Hits 87% Ahead of iOS 9 Release
iOS 8 adoption has been somewhat slower than iOS 7, with iOS 8 hitting 72% adoption in January 2015. iOS 7 was at 80% adoption at the same point. Additionally, iOS 8 reached 81% adoption in late April, only growing 6 percentage points in a little over four months.
Comparatively, the latest version of Android (5.1, aka Lollipop) sits at a 5.1% adoption rate. However, Android updates often take a long time to propagate to customers, partly because cell phone manufacturers and cellular carriers must bake in their apps and interfaces into the operating system.
According to mobile analytics firm Mixpanel, iOS 9 currently holds a ~1.04% adoption rate, which includes public beta testers and developers. That number will likely increase dramatically as the operating system will push to iOS users tomorrow, September 16.