Since this is still a Developer Preview, there are a few known bugs.
Android O was supposed to launch in early August 2017 and now popular tipster Evan Blass claims that the operating system will be officially launched on 21 August. Earlier rumors have revealed that this year Google will be releasing the Android O earlier this year.
Evan Blass Verified account @evleaks
There's really no way of telling for how long Android O for Pixel phones is going to be delayed.
Google Android O brings with it features like like improved battery performance, picture-in-picture option for apps like YouTube, Google Duo, as well as improved notifications channels. Android O comes with a multitude of back-end improvements as well such as better battery management algorithms, app optimisations, audio enhancements like improved Bluetooth audio and so on.
Also, Android Police won't publish the name on its website until someone from Google corroborates the information that they've received from its source.
The latest beta version has shown a good sign that Android O is already in a stable condition and is, in fact, due for official release anytime soon.
In addition to the double tap to zoom feature, the camera app is also adding another feature which should be useful to users - the ability to switch between the photo and video modes using a dedicated button.