This is assuming that everyone is chasing the same level of perfection as apple. If the web can provide a "good enough" interface will the bulk of developers go to the extra effort of native apps?
Currently things like games are (largely) not good enough on mobile web and so the issue is forced, but building a native app for a nicer blur effect? Probably not.
I'd argue that bulk of developers are already doing native.
The thing is, extra effort is required to replicate with web technologies even simple things that native SDKs offer.
If everything you know is HTML, JS, CSS then yes, learning iOS or Android SDK will require some effort but it is worth it.
Even the best webapps still feel subpar on iOS6, on iOS 7 they will feel very clumsy.
Currently things like games are (largely) not good enough on mobile web and so the issue is forced, but building a native app for a nicer blur effect? Probably not.