iOS 9.1 vs iOS 9: What’s New in iOS 9.1

iOS 9.1 Adds Support for Apple Pencil

Although this isn't going to help you use the new Apple Pencil on your iPad Air 2 or iPhone, the iOS 9.1 update delivers support for the Apple Pencil that is coming in November.

The iPad Pro release date is not confirmed yet, but it should arrive in early November with support for the Apple Pencil and the Apple Smart Keyboard.