This is truely unprecendented. Microsoft could screw you by cloning your app, but they never blocked third-party applications, nor tried to be the commerce gateway to the internet.
If Apple succeeds in making webapps obsolete, and competition cannot be strong enough to force it to be fairer and more reasonable in its app store policy, than to me an ipad/iphone app world sounds like a regression from the webapp world.
And this is why I never understand why so many Apple users want Android & Windows to fail. As a customer, you should want other platforms to be succesful, so that we don't end up again with a monopolistic platform that screws us all. Didn't we try this before??