All this introduction is to try to understand the Ubuntu Phone world, I don't think it can emerge against Android or iPhone, so it should definitely compete against Mozilla in emerging markets, but it looks like is coming a little bit late. I am also curious about how developers will react to the platform, with a native or HTML5 approach, looks similar to the Microsoft strategy. Firefox was able to get devs easily because the HTML5/Javascript is an easy combo and is widely known, native development requires more efforts and has a steeper learning curve. A smartphone is 20% platform and 80% ecosystem, no apps means no users.
I am honestly interested in trying it, I did it for Firefox, writing a simple weather app for it, so I would like to do the same. At the moment, I am not sure the system will be able to compete, but happy to be proven wrong!