A framework would be a start, but overall a very incomplete solution that's nowhere near as nice as the well-defined playground that is the iPhone/iPad and their corresponding app stores. JQuery and friends brought cross-browser web development, with animations, ajax, etc., into the realm of possibility for many people where it would have been completely impractical to do before. Even still, getting cross-browser apps to run when everything is written cleanly results in a lot of piled-on hacks.
The biggest problem though is a lack of a well-organized app store: centralized distribution, the arguable benefits of a review process, and most significantly the monetization framework that it provides.
BTW - great idea for startup. Create a framework to monetize web apps/software as a service similar to the one provided by the AppStore and Apple ecosystem...
The biggest problem though is a lack of a well-organized app store: centralized distribution, the arguable benefits of a review process, and most significantly the monetization framework that it provides.