Android P Developer Preview Beta 2 has been released by Google. Android P Developer Preview Beta 2 devices include the Google Pixel, Google Pixel XL, Google Pixel 2 and Google Pixel 2 XL. To receive the update OTA you need to enroll your Pixel in the Android Beta Program by following the source link OTA/flash. You can also flash the factory image if your Pixel has an unlocked bootloader.
Android P Developer Preview Beta 2 includes the final Android P APIs and an updated SDK. While Pixel owners can install the update keep in mind that it really is aimed at developers only, and could be buggy.
If you're interested in loading Android P Developer Preview Beta 2 on your Pixel device via an OTA update or flashing it using a factory image, click on the source links.
One major change includes the "clear all" button once you swipe to the left while in the app switcher. The update also includes the June 5, 2018 Android security patch.
If you don't have a Pixel, keep checking in. Google could soon release the Android P developer preview beta 2 to non-Pixel devices such as the OnePlus 6, Essential Phone, Xiaomi Mi Mix 2S, Sony Xperia XZ2, Nokia 7 Plus, Oppo R15 Pro, Vivo X21 and the Vivo X21 UD.
Source: Android Developer blog, Google Android Beta Program