Sorry I'm sure this has been asked before, but did they state why they didn't change the aspect ratio to 16:9, since this was shot on film? It seems like since they were doing the restoration/upgrade to HD they could have done that. A little late to the bandwagon, I just started picking these up. It looks GORGEOUS, just wondered why there's those black bars on the sides when it seems like they could have optimized it. I hear that they're restoring Seinfeld similarly, but ARE giving that the 16:9 treatment.
I think that there's a misunderstanding that film-based sources are automatically shot in 16:9 AR. This is not the case, as shown by Star Trek-TOS. Even going back to the beginning of film as an art form, the first films were in 4:3 AR. There have been about 10 or so distinct ARs for film over the past century. 16:9 was seen as a mean between 4:3 and the widest of the wide-film formats. 16:9 is recent. It's a good median. But I'm not for stretch-o-vision (making 4:3 content 16:9 by distorting the content). I think we should respect directorial intent. Do less, not more. A great example of this is 2001: A Space Odyssey's restoration for its Blu-Ray release. Another one? The Wizard of Oz. Without a doubt, the best the film has looked, and quite possibly the best restoration of classic films.