I am interested in the history of economic, marketing and design choices made by the company, that shaped the product line (or individual sets) and the LEGO experience that we all love. Preferably about the post-2000 years.
Yes, there actually is a book that discusses just this subject AND it's primarily focused on the post-2000 years:
Brick by Brick: How LEGO Rewrote the Rules of Innovation and Conquered the Global Toy Industry by David Robertson.
I highly recommend this book - while professing to be a business book, it gives huge insight into the companies design-reasoning and history.
Amazon Link here.