There are two huge issues with the Blu-ray Player app:
- lip-sync issues when the console is set to 24Hz Blu-ray Video Playback.
- No HDMI audio pass-through to receiver.
The lip-sync issue is quite bad. If I disable the "24Hz Video Playback" in the console System Settings, lip-sync is fine. My HDTV supports 24Hz video, and I expect the Xbox One to properly support this. I have a Pioneer VSX-32 which supports 24Hz HDMI, and decodes all HD audio codecs (DTS-MA, Dolby TrueHD, etc.) In order for the Blu-ray player app to be of any use for me, it must have these two issues fixed.