I wonder where does Firefox for Android falls under, Firefox or mobile browsers? Although I don't know if it's significant, but when I last checked AppBrain, Firefox for Android had over 250,000 downloads.

It may be hard to count. I change my user agent on my phone so that I don't get the mobile version if websites. With current phone resolutions I prefer to see the full page and zoom than have an often crappy mobile specific site that shows me less and makes me click more.