Not in the current stage of FxOS, since Gaia (the UI) seems to fail to deliver anything 'new' to a plain consumer.

For FxOS to really stand out in developing countries it would require a lot more than what it is providing now. In my opinion, since we are partly already doing communications for free trough Facebook and Twitter, something like P2P connections between the FxOS devices does sound doable for me, both for text and voice. In addition, if you could implement something like Twilio for actual calls it would strip down costs both for mainland and international calls. For reference, where I live calls trough Twilio are six to sixteen times cheaper than what my carrier can provide. This way, you would also avoid the need to sign a contract with a carrier. I believe that this form of carrierless phone would appeal to the crowd the FxOS is trying to reach.

I'm not trying to be rude but do you know anything about FxOS and its goals and architecture?

1. Does the current admission by the US government of comprehensive NSA spying on the entire internet interest plain consumers? No, it doesn't. "Plain consumers" don't understand the implications nor the technology behind it. So to ask if a "plain consumer" would be interested in FxOS is to miss the point. The "plain consumer" does not have the knowledge to judge the issue and Mozilla is not trying to become a billion dollar corporation to rival Apple or Google.

2. The architecture of FxOS is completely different for a reason so IMO, no, it wouldn't make sense to fork Android.