It has been a long time coming and especially after the number of rumors and speculation that has mounted over the last few weeks. Either way, Android 5.1 (Lollipop) had finally been announced and officially introduced. If you own a Nexus device then you will be in line to receive the update first. This will come in the form of a typical over-the-air (OTA) update. If, however, you do not want to wait for the OTA to be pushed to your device then you can download the OTA from the list below.
The zip files listed are direct links of the OTA from Google and as such are safe to install. As the OTA's become available, the list below will be updated. So if your device is not currently listed then check back often until you see the link. As usual, these updates will require sideloading using ADB. Not to mention, that is important you only flash images which list your current build number. This is listed as the "from build" alongside each Nexus device listing.