Happy Lollipop day! Google has announced that OTA updates for Android 5.0 are rolling out to most Nexus devices now. The Wi-Fi Nexus 7s, Nexus 5, and Nexus 10 are all going from KitKat to Lollipop. A post on the Nexus help forums laid out the specifics:
The over-the-air update for Lollipop is now starting! The update is starting for these devices:
Nexus 6: Minor update to address bugs
Nexus 9: Minor update to address bugs
Nexus 5: Update from KitKat to Lollipop
Nexus 7 WiFi (2012 & 2013): Update from KitKat to Lollipop
Nexus 10: Update from KitKat to Lollipop
It will also be put up on Android Open Source Project (AOSP).
Note: The OTA update for 3G/LTE versions of the Nexus 7 2012 and 2013 have not yet started, nor have they started for the Nexus 4!
The Nexus 6 and 9 are getting "minor" bugfix updates, too. We're still waiting on OTAs for the Nexus 4 and cellular versions of the Nexus 7. We're also waiting on factory images to be posted on the Nexus Factory Image page. Users can't do much to get an OTA, which can take several weeks to roll out to the entire device user base, but a factory image can be downloaded and applied right way with a little command line know-how.
The Android update schedule has been a bit of a surprise this year, as Google's Nexus devices, which are typically the first to update, were beaten by Motorola.