HTC has confirmed that the Google Play Edition of their HTC One M7 will receive an update to Android 5.1 Lollipop, with all other versions of the phone stopping at Android 5.0.
@kennymaclean Only the GPE version of M7 will receive 5.1. Our target is early April. Thanks.— Mo Versi (@moversi) March 18, 2015
The rollout of the Android 5.0 Lollipop update began for the HTC One M7 earlier this year. It is now available for the Sprint, T-Mobile and C Spire versions of the phone, along with the developer and unlocked editions.
Newer model: HTC One M9