It sounds like UIKit Dynamics will make things like flicking tiles around a lot easier to implement, without creating a physics engine from scratch... And UIKit is generally more friendly to flat designs... And the whole game engine thing is built in now.

But the real value of the best games comes from game-play dynamics, and not just how well the app simulates physics. Hopefully these changes in iOS will allow game-builders to focus more on the things that really matter, rather than redoing the work every game needs to do.