I really want an option to provide some private narratives to one or more characters. For example, I just started a game but I felt the need to write intros for each of my characters which provided them with additional background on where they came from and why they were at the opening scene. As neither of the characters in my story have met yet, I felt it appropriate to send these intros via email to each individual. It would be nice to have a mechanism in-game to do that.

I can also foresee other instances where different players may actually see different things in a scene - I think that it would be useful to have the option to NOT allow the other players to see what everyone else is seeing - which could be accomplished through some sort of side-channel as a narrator's add-on commentary meant only for an individual.