I'm calling it now: this is for augmented reality displays and similar. You want an RTOS for loss and predictable latency. And current GUIs aren't really suited to 3D environments you can walk around inside.
This is Google's next Android, with a low latency rendering pipeline for the next generation of mobile devices.
Wouldn't that be nice after Google has affirmed again and again that Java would be the only supported way to develop Android apps, even though they keep Dart funded internally...
I predict this will end up being a completely new platform.
It will share nothing with the present Android architecture initially. They'll probably shove in an Android sandbox, so that you can run some existing Android apps and stick them somewhere in your virtual space. But those won't be native apps on this new platform.
The new apps will have drastically different needs, input methods and such.
Consider the simple example of a new turn-by-turn navigation app. It will have a waypoint shown in your field of view, with an arrow pointing to the next waypoint after it. It has to 'stick' in a virtual location that corresponds to a physical one.
There's no way to do that sort of thing with the existing Android API, the concepts simply don't exist. Rather than have everyone write their own (like video games do that implement navigation inside the game world), they'll create a new API for this. And a whole new operating system.
When did they "affirm" that? They've said a couple times that "Java at this time is the only way to build apps," etc. They never ruled it out for the future, AFAIK. Please feel free to prove me wrong, but I would honestly be surprised if you found anything.
Having been to the last several I/Os where the question is asked at the fireside chats, the answer has always been "right now...". No one is saying dump Java, but if we could get some native hooks through something like Dart, that would be pretty awesome.
"Java at this time is the only way to build apps" is the right answer for Android OS, because the Android OS is a combination of an app runtime and a Java middleware layer. Adding another runtime to Android would make it a second class citizen, or it would involve building a parallel middleware. What they really mean is that the result would be messy, and it wouldn't be Android-as-we-know-it.
You can, of course, move the Android middleware layer to other OSs, for Android compatibility. Which is how you can run Android apps alongside Tizen apps: https://youtu.be/nmiHPcHGgSM
Android was designed for one runtime, Dalvik and later ART. But there is nothing preventing a new OS being designed for multiple runtimes that includes runtime support for Android apps.
I'm generally not sympathetic to Java complainers. If you have Android Studio, or any other decent IDE, verbosity isn't a problem. But an OS built for Dart apps and a Dart UI stack would be the logical next step.
Brian has been talking about how much he hates Java, its programming model, event loop, and everything else about it for many years, to anyone who will listen. Tastefully chosen for the augmented reality, self-organizing, and real-time use cases, the building blocks: UI, rendering, and app framework, all this looks like what he would create for the next generation of connected devices, of which phones are just a momentarily important example. Without Andy Rubin shoving a tech stack down his throat, I would add. I am somewhat disappointed by the DART choice, but overall really excited to see what this turns into. Great that it is open source for now, but this is Google, so you know where that will go.
This is Google's next Android, with a low latency rendering pipeline for the next generation of mobile devices.