To me this seems obvious. The higher resolution offered by 1080i will be a far more obvious improvement to the consumer than 720p. Many people do not even know what progressive scan is! Digital TV is currenty broadcast at about 575x1000 so 720p would not be that big a step forward. (In the US it has been a popular format because they had a much lower resolution before.) Plus, 100Hz scanning on interlaced DVD material is often seen as being better than the 50Hz progressive signal so would 720p be better than 1080i scanned 100Hz? With film source detection if we had 1080i we could get 1080p for movies! How good would that be!