What have I read at the AMA? This is how I see it:
Mozilla has been doing a mobile phone os with a firm belief in openness, and because they are not keen on negotiations with hardware makers and telcos, they are dropping the project, for somehow perceived lack of user base.
Then they are going to engage on some not yet clear ideas regarding IoT or TVs or something else, so they are going to partner with hardware makers and telcos (as IoT devices are not isolated islands) and try to create something with no current user base.
Right me if I'm wrong, but I don't know where one can find success on the new project. And it's not that I don't want Mozilla succeeding, as I like both Mozilla and IoT, but I'm totally pissed off for they dropping FxOS with such a lack of care for their users (yes, it HAS users), developers and contributors.
This is going to itch, but they might just drop Firefox desktop browser as well, it's a browser that has been losing market share at least on the last seven years, so they should drop it too and focus on some other fancy new project instead:
[EDIT] Oh, and I forgot to mention that Ari is going to get a RaspberryPi, a few sensors and learn some IoT protocols, and try to come up with ideas for their new phase. THIS IS NOT SERIOUS. You don't drop a whole project without a clear idea of what you want to do next.