The more we rely on CSS to layout our websites, the more complex the CSS gets. The files get larger and the cascade gets more difficult to oversee. The lack of a good structural system can quickly lead to chaotic stylesheets, and can make it a real pain to debug when encountering strange browser behavior. Instead of fixing the problems at the root, we are often tempted to fork our CSS for different browsers, or to just add patch after patch, which can often break other things.
The need for a clean structure, for our own sake, is obvious. Over at the css-discuss wiki, there is now a collection of insightful articles concerning Maintainable CSS. Since it’s a wiki, you are free to extend the collection if you have links or information on the subject you deem worthwhile.