Google just launched the developer preview of Android 8.1. The headline feature of the OS update seems to be a new "Neural Networks API" (NNAPI), which Google says "provides apps with hardware acceleration for on-device machine learning operations."
"Hardware acceleration" sounds a lot like an API that will make use of the "Pixel Visual Core," the extra Google-designed SoC present in the Pixel 2. We were told Google's chip would be enabled with Android 8.1, but it's odd that Google's announcement doesn't mention it by name. Perhaps the NNAPI will use the Pixel Visual Core on the Pixel 2, but on other devices it will use whatever other special hardware is available.
Other than the "NNAPI," there aren't a ton of changes outlined in Google's documentation. There are a few updates or bug fixes for things like autofill and notifications, but we'll have to dig in ourselves to find any other interesting items.
The beta is available for the Pixel 2 and 2 XL, the Pixel 1 and 1 XL, the Pixel C tablet, and the Nexus 6P and 5X. If you have a Google phone, you can opt in to the beta at Android.com/beta or manually flash your device with a system image. The new release bumps Android development to "API level 27," and the Play Store is currently accepting apps targeting this new OS update.
The timeline for the final Android 8.1 release is shorter than usual. There will only be two preview releases. Google is calling this first release a "beta" with "final APIs," and preview 2 will launch sometime in November and offer "near-final system images for final testing." The final release will come sometime during or after December.