Apple Pencil & Smart Keyboard
Although supply may be tight, you should expect to see the Apple Pencil and Apple Smart Keyboard on sale at the same time as the new iPad Pro.
The Apple Pencil is a stylus that charges in a Lightning port. You can charge it in the iPad Pro Lightning slot, but we just learned that there will be an adapter to use a regular Lighting cable to charge it.
Apple's iPad Pro Smart Keyboard attaches to the iPad Pro and draws power from it so that you have a case and a dull size keyboard.
The Apple Pencil is $99 and the Apple Smart Keyboard is $169.