After being rolled out Android 8.0 Oreo for OnePlus 3 and 3T, OnePlus just released the Android 8.0 Oreo for OnePlus 5, in Beta channel though. The OxygenOS Open Beat 1 update will get on your device via OTA, if joined for OxygenOS Open Beta program. Others should download the full firmware and flash it manually as described below.
HTC starts rolling out Android 8.0 Oreo stable (build 2.31.709.1) update for HTC U11 with a number of new features, enhancements, bug fixes and November 2017 Google security patches. The OTA (over-the-air) update weighs around 1.3GB and all HTC U11 units will get the update in the coming days. You can also download and install the update manually.
Followed by popular OEMs like Samsung, Essential has also started beta testing latest Android version Oreo 8.0 for their device. If you own Essential PH-1, you can now download and install the Android 8.0 Oreo Beta factory image (build OPM1.170911.130) and experience features of latest Android version on it. If you are interested, here is how to download the Essential Phone Oreo Beta 1 firmware and how to install it on Essential PH-1.
Samsung has released the second beta of Android 8.0 Oreo firmware (Samsung Experience 9.0) for Galaxy S8 and S8 Plus. The OTA (over the air) update with build number XXU1ZQK4 is now seeding to all Galaxy S8/S8 Plus runs on previous beta build XXU1ZQJJ. The new Beta update includes a bunch of optimizations, bug fixes and new features, alongside October 2017 security patches.
Moto G4 Play will not get Android 8.0 Oreo update officially, but you can upgrade the device to Android 8.0 Oreo via custom AOSP ROM. An unofficial version of crDroid Oreo ROM is released for Moto G4 Play (code-named harpia). If your Moto G4 Play is unlocked and have installed latest version of TWRP recovery on it, then you can install the crDroid ROM (version 4.0). The ROM is based on LineageOS 15.
As we know, Samsung has started Beta testing Android 8.0 Oreo as Samsung Experience 9.0 for Galaxy S8 and Galaxy S8 Plus, but it is only available in select region. However, if you would like to taste the Oreo beta on your Galaxy S8, then you can try it right now, if your Galaxy S8 is Exynos variant (SM-G950F) and have latest version of TWRP custom recovery installed on the device.