The argument that you can make iPhone web apps that are “good enough” misses the entire point of iPhone apps — the entire point of the iPhone itself, even — all of the things that drive Twitter users to pay $3, $4, or $5 for apps that do the same things that can be done for free by loading Twitter’s web site in MobileSafari. “Good enough” is not good enough on the iPhone.
[…]
A combination of increasing CPU performance, further improvements to WebKit and the Nitro JavaScript interpreter, more RAM, and additional web app capabilities in the iPhone OS (things like access to the camera and image library) could, combined, make for a future where some types of iPhone web apps aren’t just “good enough” but are truly indistinguishable from native CocoaTouch apps. The hardware performance improvements are inevitable, but it remains to be seen whether Apple will provide deeper and more significant iPhone OS-specific hooks for web apps. I hope they do. I think it would be good for everyone — Apple, developers, and iPhone users — if unrestricted web apps became a serious alternative to the restricted App Store. But it isn’t credible to argue that they already are.
