A friend brought up a good point the other day that the popularity of the iOS app store has actually pushed back on advances in web technologies on mobile devices. Because the sanctioned way to sell applications must go through Apple, less attention overall has been spent building mobile webapps. Also, since the hardware is also out of developer's control, there hasn't been a push to make native hardware available to the javascript.

Even with that, I do think that we're on the cusp of a big webapp revolution (again). With all these emerging JS frameworks (backbone, ember, derby, knockout, etc), and the modern and capable webkit powering so many mobile devices, developers will take note.