Android 5.0 Lollipop update already started rolling out to many devices and the HTC One M8 on Verizon is the latest device which can be updated to Lollipop firmware. The update already started rolling out and the users will be notified with the upgrade message. The HTC One M8 for Sprint and T-Mobile already got the latest firmware update.
The Lollipop update for Verizon HTC One M8 is via OTA (over-the-air). The users will get the update message in the notification bar or else can also be checked manually by going to Settings > About Phone > Software update.
The Android 5.0 Lollipop update brings much better improvements to the HTC One M8 including the brand new ART runtime and Material design update for the device native applications. It also adds a new card-like multitasking menu and gives a new notification style for the lock screen.