Given the spread of the device APIs that Mozilla was forced to develop for Firefox OS, I think it is clear that Firefox OS has already done more for Mozilla's mission than maintaining the previous embeddings ever could.

"Our mission is to promote openness, innovation & opportunity on the Web."

It's not clear to me that FireFox OS has done anything for Mozilla's mission. Indeed, the Firefox OS home page seems to indicate Firefox's goal is to provide carriers and OEMs with an alternative to Android, and help them maintain customer relationships. WTF? Open source vendor lockin?