Factory images are up for the Android 7.1.2 Nougat beta for anyone that's interested in installing the software onto their supported device instead of waiting for Google to push out the software over-the-air. Google just announced the Android 7.1.2 public beta as of yesterday and they stated that they would begin pushing the software out to users who were enrolled in the Android Beta Program at the same time, but that doesn't mean that everyone who was enrolled before the announcement would get it yesterday. This makes it all the more useful that Google readily has the factory images available for users to flash manually if they prefer to install the software through this method.
There are two different builds that are available for download, which includes build NPG05D and build NPG05E. The images are available to download for every device that Google stated would be getting access to the Android 7.1.2 Nougat beta, save for the Nexus 5X and Nexus 6P. At the moment the Nexus 6P is planned for a later release of the beta software while the Nexus 5X image just hasn't surfaced yet. This means that if you have the Pixel, Pixel XL, Pixel C tablet, or the Nexus Player, then you should be able to grab the factory images and flash them over to your device.
There is currently no indication when Google will push out the factory image for either of 2015's Nexus phones but if you're running the Nexus 5X then there is always a chance that the factory image will simply hit the web later today as it's supposed to be made available at the same time as the other devices. Google hasn't mentioned what exactly is new with this update, but they did note in their initial announcement yesterday that Android 7.1.2 is about big fixes and refinements to improve the software and user experience, so users shouldn't be expecting any huge feature adds this time around. That doesn't mean that there won't be any at all, but if there are any new features they'll likely be small and probably not something that will be used every single day by all users. Since this is a beta, it's also important that users go in with realistic expectations for the software, and that means that some things may not work as intended and there could be things which are broken or may need a little bit of adjustment.