Mobile devices fill a different "comfort", I think. Desktop OS's out there try to fill a broad spectrum of wants (and needs). I think Linus has been quoted as saying something like, "Desktop is a hard problem to solve", and that the Linux world hasn't even come close to solving it (yet).
I know a lot of people who would otherwise be lost on a Windows machine be completely comfortable with iPhone or Android devices simply because it fills that niche. Computer illiterate people seem to gravitate to, not desktop, but mobile devices.
So maybe Android is the new "desktop" for those types of users. Power users are now left to fill their own comforts. Maybe Linux powered desktops will eventually be the winner in the future. We'll see.
Open source codec race is, as far as I'm concerned, not over yet. Opus shows a ton of potential for audio related streaming/recording. Webm is supported by most browsers (except for Safari and IE). It's not a bad container, too. Compared to mp4, it's not that great, but I really can't tell the difference when watching something online anymore.
So, the wars aren't over. Android with Google's backing will be, and is, a force to be reckoned with. However, I wouldn't cancel out the possibility of another open source and free alternative coming around the corner to change that. Perhaps Firefox OS, who knows?