Today, Google is releasing Android 11 Developer Preview 3, which is actually the fifth build that the company has released. That's because Developer Preview 1 and 2 had minor bug fix updates that arrived a couple of weeks after.
Most of the changes with this build are under-the-hood stuff that applies to developers. There's an API that can be used to report why an app is exited, such as a system crash. There's also a revamped wireless ADB experience, which is meant to be much easier in light of more and more laptops not having USB Type-A ports. Also, installing large APKs is up to 10 times faster.
While none of that is particularly exciting from an end user point of view, the big news is that this is likely the final Developer Preview before the public beta testing period begins. While Developer Previews are publicly available, you still have to manually flash the image. The Android Beta Program, aside from being more stable, lets you easily enroll your device, and you'll get an OTA update.
Android 11 Developer Preview 3 is available now for Pixel 2 and later devices. You can flash it, or you should get an OTA update if you've flashed an earlier build.