Well, with Order of the Phoenix, Warner has pulled out the stops and has pitted interactivity vs HD supplemental video, because while the HD DVD version includes Warner's IME and web content, the Blu-ray version includes HD supplements and a 44 minute high-def TV special called, The Hidden Secrets of Harry Potter -- that was left out of the HD DVD version completely. The other big difference enabled by Blu-ray's additional capacity is an extensive list of foreign language surround sound tracks and sub-titles -- at the same time the HD DVD is a combo disc without the $10 premium. So dual format owners will have to choose between interactivity and HD supplements -- or maybe they'll just choose to save $5 and go with the Blu-ray version.