A feature I'd love to see implemented in Plex is the ability for two Plex Players, connected to the same PMS, to watch a Show / Movie at the the same time.
Example: I am in New York, connected to by PMS in New York. My brother is in California, and is connected to my PMS via Roku or iPad. My brother is watching The Incredibles, and is 35 minutes into the movie.
I decide I want to watch the Movie with him as well, so I give him a call, and I load up my Plex Player and select "Play The Incredibles - Join current Session". My Plex Player will start playing the movie and jump to where he is playing now - so that we are in sync while watching.
It's the same idea as watching LIVE TV from two locations.