Let's see where this stands three years from now.

Mozilla is working on some pretty neat stuff; and is paying attention to the rest of the world, not just the American/European/Japanese market.

Also since they are a foundation owned corporation with a public benefit mission https://www.mozilla.org/en-US/foundation/moco/ they can take a longer-term view than some of the other big players.

Having played with one of the flame dev phones for FirefoxOS I wouldn't be too surprised if within the decade they are dominant in areas of the world that don't have an installed base ( rural india, sub-saharan africa outside of SA, etc. ).

Remember that more people are going to acquire mobile internet devices in the next 5 years than were on the internet in 1998.