IMO FirefoxOS wasn't well received partly because it wasn't Android-based. Ultimately I wouldn't try to do a mobile OS without ~$10B in marketing/ecosystem funding.
I'd love to see this too. Would love it if it was an OS that scaled well from desktop to mobile (at least tablet) sizes. I'm a big fan of the basic idea behind Chrome OS. Not so much a fan of giving Google my info. Would be nice to have a real alternative in this niche.