Yes, this is under developer’s NDA so I won’t go into details.
But it looks pretty damn similar with cocos2d (and even with box2d) and people started wondering what will happen with cocos2d-iphone.
I played a bit with the SpriteKit and I think it could use a lot of optimisations and tweaking. Anyway it will be a more “native” solution for 2d games, than cocos2d so people will be encouraged by Apple if not by the better performance itself, to migrate to using it.
riq from cocos2d-iphone already stated that he will probably put the project in maintenance mode and focus even more on cocos2d-x.
Most of the cocos2d games are anyway developed on cocos2d-x for its portability, and considering that cocos2d v3 is coming with a brand new rendering engine and extra C++ 11 features (easier to use for Objective C programmers), it won’t be an easy road for Apple to get developers to the SpriteKit way.
In the end, that is good for both parties; competition is always good. I am still waiting to see if they will add any 3d features to this framework – that would be really interesting.