I recently attended a webinar by Harlan Kilstein and Tom Beal about blog curation that also went into positioning a site on Google without any black-hat tricks that SEO consultants have been trying to sell for thousands of dollars.
I've been saying the same thing and predicting some of Google's recent moves for years. But my potential clients wanted results that I couldn't promise and I actually had some potential clients stand-up and walk away from a meeting with me when I said I wasn't going to use any black-hat techniques.
This is a real world example of using a series of flat taxonomy lists to categorize information. We'll be categorizing BMW car models and organizing them by car style and engine displacement. Since the car styles can get complex and car models can have more than one body style but we want don't want any cars listed more than once so we are going to use the flat lists I talked about. The other kind of lists go much deeper into Computer Science theory and data structures.