If you have been waiting for Android 8.1, you should know that the first over the air (OTA) update has started rolling out. This is the beta build and comes shortly after the first Developer Preview went live.
To get the OTA update, you will need to have enrolled to be part of the Android Beta Program. If you are part of the Program, you should be getting a notification if you have not received one yet. It goes without saying that to be part of the Android Beta Program, you need to have a Pixel or Nexus smartphone.
If you do not have the OTA update notification, you can get this beta build by downloading and flash the factory image for yourself. Before you do this, you need to know that some users have been reporting issues when side loading OTA images but Google is working on a fix for that.