In this 3-part screencast you will be able to follow Sandro's "just in time" design approach and understand the rationale behind some of his recent comments. You will notice that he not always follow rules and how he relies more on his intuition to drive his design. Thinking out loud throughout the video, it becomes quite easy to understand everything that he is considering while writing each test and refactoring his code. This video provides a very good example of Outside-In TDD and how it differs from the Classicist approach.
If you are TDD novice, don't follow the advice from these videos blindly. Favour the classicist approach, design less up-front, and get feedback from your code before evolving your design.