what WON'T look better in high definition?

[no_wei]

So, poking around on this forum has me quite excited for the impending release of blu-ray, despite having no idea how i'm going to pay for the increasing severity of my digital video addiction.

I noticed at least one of the more recent posts concerns DVDs longevity, and I must admit, when I first started checking up on blu-ray, it occured to me that one of the most interesting side effects of blu-ray's release (and hd-dvd's release, for that matter) will be the eventual discounting of DVDs, which, in many cases, are already dirt cheap. So, my question is this:

What kind of stuff is already on DVD (or still headed to DVD) that, due to its original master format, will just simply NOT be able to improve with the move to high-definition?

My theory is the following: television that was recorded using a video format, i.e. some sort of beta; films from the early history of film, i.e. pre-sound era films that either didn't have the greatest picture quality to begin with (something like Voyage to the Moon circa 1903) or that master reels that have already degraded a good deal (i'm thinking something like Birth of a Nation, but I can't remember if it falls into this category); and, perhaps, some animation.

In one of the other threads there was some discussion about something like a Charlie Rose interview making the move to 1080p. Now, I could be way off here, but wouldn't any current (or even circa 2000) Charlie Rose interview (or pretty much any non-dramatic television show) be shot using beta, which either falls short of or is comparable to the current dvd standard? So, if the original source material is already of considerably less quality than high defintion offers, then there can't possibly be anything to gain by "increasing" the picture quality.

I think the same would be true for a lot of early film, although probably far more debatable insofar as the actual resolution of film seems to be a bit of a contentious topic. Basically my argument here is that a lot of early films had (or, due to the ravages of time, now have) picture qualities that were less than perfect. So, I think this might be an instance where you could theoretically gain additional image information, but my question is: how critical is said image information?

I ask more-or-less the same question with regard to animation. Let's take The Simpsons, for example. I am already amazed at how good it looks on DVD, and just due to the style of animation, which essentially uses large blocks of homogenous colour (i.e. Homer's blue pants), how much better can this possibly get? I imagine the original masters (which I suspect would, in fact, be a film negative) do offer a theoretically higher quality, but again, would one notice? It's not as though the image quality can be increased to the point where one could see each individual hair in Homer's stubble, because it was never animated in the original. Of course I recognize there aren't necessarily any hard and fast rules for animation, as this type of thing would become less of a concern as one moved toward something like, say, the old Aquaman cartoons or more of a concern as one moved toward an animated film like Ghost in the Shell, for example.

So, I guess that's a long way to ask this short question: what should everyone look for in DVD bargain bins in the coming months and years?

Thanks for indulging my verbosity,

/no