If this means that devs would be able to update the app on their end for troubleshooting and updates without a user ever needing to update manually, I could see this becoming extremely popular.
I don't see a difference between this and a normal Firefox browser. All I can tell is that categories in this "manifests" will be abused unless Mozilla themselves categorize a website.
[citation][nom]abbadon_34[/nom]most "apps" are just websites anyways, or a cripple portion of them[/citation]
+1. How is this anything different? Only benefit I guess would be if content was saved locally for offline browsing, but then how is this better than simply saving pages locally?