I just got my Nexus Player three days ago and one of the first things I did was check if I can play YouTube videos at 60fps. I was disappointed to see that it wasn't supported, neither through the YouTube app or Google Cast. But today, I was watching a Short Mario Maker video using Google Cast, and suddenly its the first video playing back at 60FPS. The native app still doesn't do it, but I'm alright with that.
Is it working for anyone else?
Yup, no 60fps in the app yet, but I've definitely noticed it working with Google Cast.