As i said, the work is being done on APIs. Infact in developer channels of the browser, I think all the html5 APIs are accessible to everyone. As for background

As i said, the work is being done on APIs. Infact in developer channels of the browser, I think all the html5 APIs are accessible to everyone. As for background pages, there is no way of running a background page that is hosted somewhere else because there is an internal api that allows communication between pages's javascript in realtime. And such communication would not be possible with a hosted file. And there is a thing known as installable web-apps. Which basically means you can install an app with just one manifest file hosted online. (it used to be in about:flags but now i think it has landed in stable release, but not sure). Which means no hassle of webstore or even maintaining a separate crx file, just upload a manifest.js once and forget :) Unfortunately background processing is not possible in hosted apps, just in installable ones.