The rumor is coming from component manufacturers, though of course none of the sources were named. But they did also include/invent details like a rumored price tag of $100 to $200 with a launch scheduled for some time in the middle half of the year.
So Amazon has a smartphone (again). In spite of my disbelieving tone, I tend to believe this rumor is true. The last time a similar rumor came around, first Bloomberg and then the WSJ reported that Amazon was thinking about a smartphone. That's a pretty solid set of corroborating rumormongers.
And if they're right then so could the earliest rumor, the one which said that this smartphone would have a 4.3" screen with qHD resolution (960x540) and be running a highly specialized version of Android on a 1GHz dual core CPU.
TBH, by next summer those supposed specs would make this smartphone more than a little dated, so I'm not sure they're reliable.