It is interesting to note that Nexus devices did not get Android (5.0) Lollipop on Nov 03, however Google never revealed the official date but unofficially it was in news that Google will roll out the Lollipop for Nexus devices on Nov 03. So why it got delayed?
As it turns out, Google found some major bugs in the developer preview of the Android 5.0 build, particularly one related to Wi-Fi, which drains the battery.
Although Google has seemingly fixed the bug now, the unofficial release date has been pushed back to November 12, after which you’ll start seeing the rollout on Nexus devices, starting with Nexus 7.