Folks who own the HTC One M8 on T-Mobile's network might be pleased to find the new version of Android on their device today or very soon. Android 5.0 Lollipop just started rolling out today. The software version is 4.20.531.4, and, of course it includes the latest version of HTC's Sense 6 overlay. It's a hefty 634MB, so be prepared to perform the update over "the Why-Fi's."
If you would like to get the update started early you can try the usual Settings>About>Software update>Check now, but it will likely roll out in waves, so your device may not be in the first batch.