Google had released the Android 5.0 Lollipop a lot before, and still most of the flagships have not been updated yet by the respective mobile manufacturers. And seems like the next big update is already out. Though the update is not as big to change the version number, but still seems like a decent update.
We had received the half announcement from Google last week about the version 5.1. And the version is in testing with the Nexus 5. This is quite surprising as the latest Nexus gets and receives the update, and the testing has to be performed on it, but still this time Nexus 5 is the lucky one, leaving the Nexus 6 alone.
Also a benchmark report spotted a nexus 5 running on the 5.1 version of the mobile platform. So it is clear the update is about to come, as it is in testing and almost up and done. But still there is no clue, so as to when the update will be rolled out by Google, only the time will tell.