Excellent post Nick. As was said, DVD is encoded for 480 lines. But with a quality upscaling player the image is "simulated" at 1080 or 720 to give you a higher resolution even though the DVD itself is only 480. It does not look like true HD but sometimes it gets quite close. On very good transfers like the Matrix or the Star Wars trilogy, I would say the improvement is 50% better than standard 480p. It's a cheap way of getting the most out of standard DVDs until true HD discs are here.