Take out that automatic nonsense and I think he makes a good proposal. A URL can currently load a local app rather than a page in webkit. Only in this case, there would be some markup that would tell the browser to check for the installed app, perhaps the browser would present some unobtrusive indicator that a hybrid app was available to download. Just keep the address bar and the rest of the browser chrome there, swap the webkit frame out with the app's window, let the app access some of the history APIs, and you'd have a good portion of this figured out.