I think this is too early to be worrying about it. By the time this is actually an issue (you can't get some *new* films on one or other format at the moment) it'll be a lot easier to archive it for those who don't care about the higher resolution.
At the moment it's early adopter time, and those people are largely after eye candy for their big hi-res screens. They see downscaling as defeating the purpose.
You can't always look at the past to see the future but as you said I think the process will be slow enough that it doesn't make a huge deal.
Up until more recently you could still get VHS tapes from Blockbuster for rental and Walmart still sold VHS tapes. How long have DVDs been around? Quite awhile and you can pick up standalone DVD players for like $30 these days.
This is definitely the early adoption time along with the insane costs that go with it. I know the specs have been ratified for DVD-HD and Blu-Ray but I am hoping to wait until they shake out everything and see how many problems they discover in real world use.
(1) Look at the issue with the drives for computers when it comes to Blu-Ray. Some don't burn DL? Why not? Why would a manufacturer release one that didn't and why would anyone spend the money on it? I sure wouldn't for the prices they're asking.
(2) Look at the issues with some Blu-Ray discs that have been released. I've heard and seen some god awful releases. They promote it as the next great thing and then have the nerve to release a bad quality release when Blu-Ray is still in its infancy? This is when they should be releasing stunning quality releases to make people
want to get a Blu-Ray player and movies!
(3) HD-DVD discs haven't been 100% perfect either.
So, in short, I don't think anyone has to worry about DVDs going extinct for awhile and by then the HD-DVD and BR standalone players and PC players/burners will have dropped in price. And, if you wait long enough, you'll probably be able to get a nicely priced combo unit that handles all CD formats, DVD formats, HD-DVD formats and BR formats.
Down-converting HD to non-HD would be counter-productive, IMO, but I do understand that one of the selling points of HD/BR will be that they have features and extras that no old DVD release will ever have. So be it. That isn't enough to cause me concern.
PS: I quoted you, Faye, because I agree with what you said. I also went on to ramble about other stuff.