This is absolutely amazing to watch. Fills in so many of the gaps, and as it progressed each of my concerns ended up being addressed.
The way they're handling the modularity resolves all the concerns I had with the Phonebloks concept, the low-cost "endos" allow you to basically pick and choose from several sizes of phone and even swap the components between them to change your needs for the day on the fly, and the openness allows a complete shift in our expectations of a phone. Suddenly you can pick and choose exactly what components you want, and manufacturers can develop, openly, for this platform and I'm no longer stuck with the limitations, or extra costs, of the components that my OEM decided best fit their bottom line. I can prioritize different functions, change my priorities later and replace them, upgrade them as companies begin to compete more seriously on the individual components, and consistently maintain something that's decidedly mine.
All the modules can have their covers replaced, and those covers are easily 3D printed, meaning if I had my own equipment I could design my own, or I could easily go to a third-party and buy a potentially massive number of different covers to customize my phone to represent exactly what I want from it. And the thickness/size concerns are addressed by a very clever magnetic connector. When I saw them in action, my instinct was that a simple drop would make your phone fall apart. But apparently the magnets on the modules are electric, and their intensity is increased by an order of magnitude whenever the phone is on and functioning, to the point where a person wouldn't be able to physically force the module out.
One thing that's very cool is simply the ability to respond to any new need quickly with the same device. With SIM cards we can easily switch to another network, but most global networks have different frequency needs and not all phones can handle them. If I travel once a year, I can simply switch the antenna module out for one local to the place I'm visiting, or if I travel much more frequently maybe it's worth it to consistently upgrade it to the latest world-capable module that's got them all covered, or maybe just rent one wherever I go. Whenever your carrier upgrades their service for new functionality you can swap a module for the latest LTE bands that your last one didn't support. Maybe for work you need a barcode scanner, or infrared device, or perhaps some secured, encrypted wireless channel connectivity, or a radio scanner, or a variety of other needs, and you can swap that in when you're working, and swap it out when you're on home time.
This is highly disruptive, and it now makes perfect sense why Google held onto it. This is Android for hardware. Open, and taking the power away from monopolizing the entire device and allowing it to be divided up between any number of manufacturers, forcing more competition, better value, and more choice.