The Science of Superman documentary included in the set was a Circuit City-exclusive with the release of Superman Returns, so this is its first wide release and also its first in HD. The Look, Up in the Sky! The Amazing Story of Superman is also seeing its first HD release here. Not only are those two in HD, but we've also learned that the never-before-seen Return to Krypton alternate opening scene from Superman Returns will be included in full HD in this set. That's a very cool and appreciated touch. Also, a number of you have asked about the audio for the Superman: The Movie BDs. The 1978 Theatrical Cut Blu-ray will BOTH the 2000 mix in English 5.1 DTS-HD MA and also the original theatrical audio in English 2.0 DTS-HD MA. Naturally, the 2000 Expanded Edition Blu-ray will include the 2000 remixed audio in English 5.1 DTS-HD MA. Hope that clarifies things for you. Really, the only disappointing thing about this set is that the Fleischer Superman shorts aren't in full HD.