After 2K14's mediocre Career mode I highly doubt it would turn out to be anything spectacular this year. I also believe that (like you said) if implemented correctly it could be great, but the chances of that are HIGHLY unlikely. Instead I'm expecting some sort of linear storyline where you only interact with the few players who provided voice recording.
I just can't presume that things will turn out well if 2K14's 'big' features didn't even turn out well.