The latest video for NHL 13 focuses on the rebranded GM Connected mode, which serves as an evolution from the previous Be a GM mode.
"What's new?", you ask, skeptically. The main change is online play -- hence the "Connected" part of the name. With online play comes the ability to be apart of a 750 person league, but of course you can always go offline and play with or against the AI or a friend or friends.
There's lots more to it, so check the video below and also the source link if you're interested in the finer details. The short version of it is as far as fantasy hockey goes, this seems to be about as robust as it gets, enough so it could even be its own game. We'll see come release time (September).