Really enjoying seeing so many different aspects of a start->finish project, already including pair programming, TDD, Repository pattern. I hope you plan to continue introducing a new pattern/practice/etc each episode. I have some understanding of each, but it's nice to see the glue or process of putting them all to use in a single project.
Are you planning to release any code snippets or source? There are times when I am not fully aware of your chosen implementation details, such as where you are putting your Repository Interface in relation to namespace and project - Main vs. Test project in the solution.