At the end of the day, the distinction seems rather stupid. What is "native" anyway? We are all using frameworks, Cocoa, Android or HTML5. We are not using assembly code, after all.
So if the capabilities of the "HTML5" framework get better, the distinction will fade away. WebGL is on it's way, and so are javascript interfaces to the mobile hardware.
Cocoa and Android are the native APIs of the platform. HTML5 is an abstraction on top of Cocoa and Android; it should be obvious that it's not at the same level. HTML is the least common denominator across all platforms and is a sandbox on top of that. The distinction is a lot stronger than you make it out to be.
Android is not the native API, at least the Java API is not. What magic capabilities are there on these devices that are forever beyond the reach of JavaScript? Does Cocoa expose all possibilities of the phone to the developer (I don't think so...)?
So if the capabilities of the "HTML5" framework get better, the distinction will fade away. WebGL is on it's way, and so are javascript interfaces to the mobile hardware.