Yes, Dec 11, 2006 is the last time there will be a written Part 1 exam. Also, starting Jan 2, 2007, the exam will no longer be split into 4 distinct sections. Instead, you'll get 400 clinical scenario type questions that mix up the different subjects. If you do take the exam before 2007 and fail one section, you can still just take that one section on the retake. That option is no longer allowed for people who take the new exam. All this info should be on the ADA website.