It's interesting what Michael Steeber from 9to5mac writes in the article below is exactly the same idea I'm talking about in the video above. The idea that future iOS versions could be based on the Apple Watch UI. It's actually a perfect UI for large devices like the new iPhone 6 and iPhone 6 Plus, to be able to easily use them with one hand. Personally I'm sure that Apple will evolve iOS into more like the Apple Watch UI in a near future. Apple's future could be based on the Apple Watch. And Apple won't have one more OS that is separated from the other too (iOS and OSX) that is now merging more and more. Of course will they share the same UI and navigation in the future.
Modernizing the home screen: How iOS could take cues from the design of the Apple Watch | 9to5Mac
Moving the Apple Watch home screen to the iPhone breaks down barriers that have been part of the system since day one. Gone are the concepts of home screen pages and the dock, replaced with one large, fluid grid of apps. The app grid not only looks more modern with its round icons, but it scales perfectly to any size display, all the way from the smallest Apple Watch to the 9.7” iPad, without looking crammed or too spread out at any size.