The beta is available for all Pixel smartphones. That includes the Pixel, Pixel XL, Pixel 2, Pixel 2 XL, Pixel 3, Pixel 3 XL, Pixel 3a, and Pixel 3a XL. This is the first release candidate for Android Q, which means that it is pretty polished and almost ready to be rolled out. This is the first of two release candidates, with the second one likely coming later this month or early August, before the final version rolls out in Q3.
If you are one that wants to get this beta as soon as possible, and not wait for the OTA, then you can flash this image onto your smartphone. Remember that it is going to erase all of your data, so you are going to be starting fresh here. It also won't be receiving over-the-air updates any longer. So the best bet is to still wait for the update to actually land on your device. Which should be happening in the next couple of hours anyways.
Those that are in the Beta program, it's not a good idea to download the image and flash it onto your device, as it will break future OTAs. But it is there if you really need it right away.
This is the fifth beta for Android Q, which means we are getting onto the home stretch. This is going to be Android 10 when it is finally released in a month or two. While it is Android 10, it's not a huge update for Android as a whole. There are some pretty nice feature additions here, like the system-wide dark mode, but as far as an entire system redesign, that's not happening with Android Q. Which is probably a good thing. It shows how mature Android has gotten over the years, in the fact that it doesn't need to roll out these huge changes every year any longer.
As has been the case with the past few Android updates, Android Q is mostly an under-the-hood update. There's lots of changes for developers to work with, which will improve their apps, the way apps work on Android and also improve battery life and performance on smartphones. Especially those with lesser specs. And where there are over a billion and a half Android users on the market right now, and many of them do not have a flagship smartphone, that is definitely a good thing.
Other manufacturers like Essential, OnePlus, Sony and others, are going to be rolling out the fifth beta pretty soon. But you'll need to wait until they actually start rolling it out. These images do not work on those devices, due to the different hardware that they possess. So please do not download this firmware and attempt to flash it on your OnePlus 7 Pro or Essential PH-1. It won't end in a fun way, and will likely brick your phone, if it is even able to install on your phone.