As promised, Google has released the updated Developer Preview images of Android 5.0 Lollipop for the Nexus 5 and Nexus 7 (2013) along with the final Android 5.0 SDK for developers. 

The updated Developer Preview image for the Nexus 5 and 7 carries the build version LPX13D and can be downloaded from here.

The updated SDK can also be downloaded from the same link. If you already have Android Studio installed on your PC though, you should get a notification to install the new Android 5.0 (API 21) related files and system images when you next launch it as well.

Additionally, the company has also updated all the developer documents to reflect the new features and changes introduced in Android 5.0 Lollipop.