It’s been a long path to a phone system that has truly interchangeable parts. There is another modular phone in the market, but it doesn’t have the backing of a major manufacture, nor is it the first.
The first was the Fairphone which brought their 2nd version to market this year. They are concerned about the social and economic justice concerns of where we source our technology. Engaging with locals who can be most benefited where possible in sourcing all the component materials. It may cost more but for some it is worth it to know your dollars represent not just convenience, but your values as well.
But the new Motorola Moto Z brings support from all the national carriers, but success will be dependent on how many modules Motorola brings to the table, or if they can induce partners to make compatible bits. And of course Google is making threatening noises about Project Ara again – but they’ve been doing that for a while.