Some people here just don't seem to realize that playing 720p on N900 is pointless. Just for a clarification to those people: the N900 has a display resolution of 800x480 pixels. Anything larger than that needs to be scaled down. Now, 720p is a short-hand for 1280x720 pixels, which is rather obviously A LOT more than N900's resolution. Thus the video just gets scaled down. 480p video is actually a lot closer to N900's native resolution and because there's significantly less to decode it'll also reduce battery consumption.