Can't really think of much that it WOULD be useful for. Updating buggy discs, yes... but any other content could have been part of the original disc.
same here, except for the movie DB connection, which I am not interested in but can be interesting for others and can't work well if it is on disk.
Don't remember what studio has used it (and never tried it), but in essence you link to imdb (or something like that) and you can get a list of other movies that the actor played in or trivia about the movie.... so if are the type that after seeing a movie you want to see more from the same actor/director or you think someone looked familiar and you want to know where you saw them before, it can be useful and it is live, then again you could just go on your PC and do it :)
.
