While there is nothing official or a press note to confirm, there have been several notifications across the web on Reddit and XDA Forums that the Google Play Edition of the HTC One M8 has started receiving the Android 5.1 update. The Google Play Edition device is essentially an HTC One M8 which is running the software at heart of the Nexus 6 or stock Google Android the way they would want it.
The device may not be sold out in large quantities, but if you have used an RUU to convert your HTC M8 Sense version to the HTC M8 Google Play Edition, chances are you would be getting a notification for the update very shortly. The update is about 250 odd MB in size and brings whole set of Android 5.1 changes which includes stability, changes in interaction while interrupted notifications as well as cosmetic and animation changes here and there. There is no word on when the update will be released for the Sense variant of the HTC One M8, though you would think that another month or so would be a good time if one were to guess about the arrival estimated time.
If you own an HTC One M8 Google Play Edition, do let us know in the comments section below if you have been hit by the update yet.