We who develop digital archives do these on a project basis. I’m not going to spend my whole life on the mouse book, and there’s going to come a time when I turn this off and go on to the next thing. My hope is that then that happens, I’ll have a few hundred megabytes of material on the site– interviews, documents, pictures, and discussions from users. That material will be interesting to scholars, designers, and very strange people who are amateur mouse enthusiasts, for quite some time.
But how do you make sure your site continues to be useful after you stop working on it? We tend to consider Web sites to be “live” things, and to expect them to reflect the voice and interests of their creators (whether they’re companies or individuals). It’s very easy to assume, then, that if the creator has lost interest in the project, that the site is no longer interesting.
It may be that this is a social convention that you can’t design around; but it’s worth thinking about.