Considering that Firefox OS is targeting "the next billion" smartphone users, it's a risky but potentially disruptive project.
My 2 bits: I picked up the ZTE phone and have been enjoying playing with it, the programming model is dead simple and the features are a bit ahead of Android 1.0. But I'm really looking forward to push notification before I start writing apps for it. It seems to me that notifications are the heart of a good smartphone UX. It's on the roadmap, but I might have put it earlier.
What do you think of the roadmap? Where are they being insightful, where are they missing something important?