[Tloewald]

Downloading data and rendering a ui around it is very different from providing a general purpose HTML renderer. One is going to make you vulnerable to attacks on a single custom protocol, the other to any security issue in the rendering engine for all users of that browser. It may well be that Apple derives both business and security benefits from sticking to one HTML rendering engine, but it's simply untrue to argue there is no security benefit.

As for the iPhone being crippled — it's the only significant computer platform with no malware in the wild. And it's not for lack of interest - jail broken iPhones are not free of malware. It's a tradeoff that some customers choose to make. It's also a trade off apple thought made sense for a device we carry around, communicate with, which can track our movements, and so on.

Personally, I think the security model apple is pursuing on Mac OS X is better than that for iOS (an opt in walled garden which is what I think you want). Maybe they'll converge. But I don't think there's any evidence (so far) of insidious intent behind Apple's moves. They're figuring this stuff out as they go along, and they're being careful. One thing is pretty certain -- they can't put the genie back in the bottle, so as they ease up on security and other restrictios they need to figure out what works and what doesn't.