Google makes it very clear thought that the preview build is only for developers and not suitable for normal users although beta testing will be available soon.
Android 11 brings a ton of new features and improvements but before we dive into that, lets take a look at the release schedule.
Android 11 Release Schedule:
Android 11 Build
Developer Preview 1
Developer Preview 2
Developer Preview 3
Final Build (Stable)
Improvements and new features coming to Android 11:
Android 11 brings quite a few new things to the table with the most important one being the support for more screen types including many enhancements for foldable phones which seems to be the new up and coming trend.
Google is going to make it even easier to keep up with conversations from the notification with a dedicated sections for conversations and not only that but now users will be able to copy images from chrome and paste them into a conversation directly using Gboard without the need to save the image to the phone.
One time permission function is also being introduced with Android 11 that will allow users to grant one time temporary permission to apps for using camera or access location and so on and also expands biometrics compatibility and platform support for securely storing verifiable IDs like driving license and other documents.
There are a loads of other improvements being introduced with the Android 11 Developer Preview that will hopefully be brought forward to the stable version of Android 11.