That also means you can't easily load this up on your Pixel 2, Pixel 3, Pixel 3a, or Pixel 4 without a bit of work in adb and a command prompt. Not that it's a bad thing, on the contrary, now that the new Android OS is out, developers will have even more time to experiment with it. If you do decide to install it be mindful that this is the very first developer preview and is likely to contain numerous bugs and issues and may not be suitable for day to day use. As expected, Android 11 Developer Preview is only available for Pixel devices, namely Pixel 2/XL, Pixel 3/XL, Pixel 3a/XL, and Pixel 4/XL. That's based on an early preview of Android 11 revealed by Google today (Feb. 19).
None of the current Android 11 test devices have 5G support, but Google says 5G is a focus of Android 11. Not because we're getting an early Android 11 Developer Preview, but because it's not coming during the usual release window - March. New screen types have been added to let apps manage pinhole and waterfall displays. Many user privacy and security improvements have been added, as well as lots of connectivity, image and camera enhancements.
There's also a bandwidth estimator API that makes it easy for devs to figure out how much downstream/upstream bandwidth is available, without the app needing to poll itself or compute its own estimate. If you want to try Android 11, you'll need a Pixel device no older than the Pixel 2/2 XL. This means apps can access the permission until you move away from the app, and then they must ask you again.
For the Pixel 4 and 4 XL specifically, there's a new Motion Sense gesture to pause music, as well as an option to increase touch sensitivity when using a screen protector.