The state of Android P at the start of the Developer Preview route seems a little more raw than what Android Oreo had began with. Nevertheless, the first preview was released today as the alpha build of what may ultimately become Android 9.0.
Google has now scheduled four more developer preview stages before a final release sometime in the third quarter — PhoneDog was able to extract a graphic detailing the schedule.
The second preview, which will bring P to beta stage, is likely to surface in early May, around when the Google I/O conference is taking place. APIs will be finalized with the third preview come early June. Preview 4 will come later that month as a release candidate and Preview 5 will allow for final testing in late July.
The Pixel 2, Pixel 2 XL, Pixel, Pixel XL and Pixel C are eligible to flash this preview build. The Android Beta Program will restart for this iteration at a later date.