It worked for me last night, NHL.tv app on my Android phone to my Chromecast enabled TV.
I have to play more with it, but I noticed that even playing an archive game via phone to Chromecast, I couldn't fast forward or rewind, just pause. That's stupid given they no longer remove pre-game, intermission, or commercials from the videos. I hope some day they'll get back to the level of functionality before MLBAM.
Note: last I checked, PS3 can start live games from the beginning. I'll try tonight if I get a chance and report if that's broken now too.