Last week he led a webcast, "Outside-in TDD and Unit Test Isolation with Python, Django and Selenium." It was almost 2 hours, lots of Good stuff. He started by explaining traditional (inside-out) TDD and then contrasted to outside-in, all in the context of a webapp.
O'Reilly dropped a 50% discount code during the webcast, not sure how long it will last: "WCYAZ".
I "watched" the webcast live, but was on my phone which only provided the audio stream and not the slides. I'm looking forward to watching the archive and reading the book.