HTC M8 has not been made official yet but it has been leaked a couple of times. Now, we have a 14-min German video review of the device in full-HD format.
Apart from showing the handset physically in the video, it shows us some software features of the device including the new UI. You can also see the demo of the new dual cameras and some software features offered with it.
HTC M8 is expected to be officially announced on March 25th but it won't be a surprise any more as most of of the handset features are already out.