Google has released Android 5.0 Lollipop factory images for the Nexus 9 tablet and the Nexus Player Android streaming device. The Android 5.0 binaries are available for the Nexus Player, but it is yet to release binaries for the Nexus 9 tablet included in the factory images itself. Google recently pushed Android 5.0 Lollipop source code to AOSP.
The Android 5.0 Lollipop update brings Material Design with bold, colorful, and responsive UI design, better notifications, battery saver feature, better security including Android Smart Lock, New Quick Settings, Improved network handoffs, flexible sharing, faster, smoother and more powerful experience with ART, 15 new languages and more.
Nexus devices, including the Nexus 4 should get the Android 5.0 Lollipop over-the-air (OTA) update soon. Google is also expected to release the factory images and the binaries for these devices for these at the time of the roll out. You can download the factory images for the Nexus 9 and Nexus Player devices from the Google Developers website here.