Mere hours after Vodafone Australia indicated that the Nexus 6P Nougat update was being delayed by an issue Huawei had discovered, the problem seems to have been resolved since the update is now available. We still don’t know what the issue was, and we still don’t have updates for the Nexus 6 or Nexus 9 LTE. Nevertheless, you can now either flash the factory image in fastboot mode (in which case you’ll want to back up your data on your PC beforehand since your storage will be wiped) or flash the OTA update through your recovery and ADB (instructions on Google’s site).
Custom ROM developers have also been patiently waiting for the factory images to be available so they can use the official Nougat proprietary “blobs”(think device drivers) to build their unique takes on Android 7.0. While it has definitely been possible to build using the open-source components recently pushed to AOSP in combination with the proprietary device drivers from Marshmallow or one of the Developer Preview builds, that approach has always been more prone to bugs and many developers just aren’t willing to attach their brand name to such a patchwork build.
Of course, they no longer need to choose between waiting for the latest “blobs” or building a patchwork ROM, but that doesn’t mean we’ll suddenly see a flood of Nougat ROMs for the Nexus 6P. You might see a few mostly-stock builds in the next few days, but it takes quite a while to rebuild the more customized ROM features into a new version of Android.