That's a good question. I'm a bit of weirdo in that I'll actually track down some of that old stuff if it's not too expensive and can perform better than modern alternatives (a rare combination). But I think you're right in that the community could quickly just become a place for people to post their old stuff, which isn't much help for others who are looking for something that's quality and still easily obrained.
I think I'll take the stance that this BIFL will be solely focused on things that are still being made, and make that a hard rule (once I get around to editing the sidebar).