I think the key question is where will the consumers go? Android is more open than iOS, but devs continue to build for iOS first b/c that's where all the users are at, especially the paying users.

I only know a little bit about the Firefox OS project, but if you give control to the OEMs, won't you run into the same problem that Android has with fragmentation?

On one hand, I don't want to be naive. Everything on the desktop has moved into the browser. That happened a lot faster than I though. Everything in mobile is moving 2x the speed of desktop, so will everything move onto a browser in mobile eventually too? The key difference between the desktop and mobile is that there isn't hardware ubiquity. Every computer has a keyboard and a mouse. But the hardware buttons aren't standardized across Apple and Android. The home button is crucial on the iPhone and same with Android. Would either of those platforms ever cede control over that button to a browser? Otherwise, you've got to put that functionality on the screen which takes up space.