When the Watch is released in two weeks time, one of its features will be the ability to customize the watch face with widgets showing you your next meeting, the weather, your fitness stats and so on.
It's a cool feature that instantly customizes and personilizes your watch.
Imagine Apple allowing the same for the iPhone's home screen. Add the weather, stocks, ... Or even change the clock into another format, add a calendar showing the current month or replace the Camera shortcut with a shortcut to another app.
Maybe this won't happen in iOS 9. But somewhere down the line they have to do a back to the phone event where Apple adds Force Touch and Taptic Feedback to the iPhone too. Migrating software features like this uber-personalization should be on that list too.