So, that two-disc edition of The Dark Knight has to be the definitive edition, chock-full of extras, right? Well, let's just say, sort of. There are plenty of extras here -- and plenty of them are truly terrific. But you will feel like there's some stuff missing, too. It's surely being saved for the big, fat ultimate collector's edition that will come out soon enough (maybe they're saving something for a set of all of the Nolan Batman movies someday). But for now, this two-disc edition is what we get, and there's plenty here to sink your teeth into.