Higher res video still would look better than a lower res or a pixel matching resolution (800x480) video on the N900's screen. I did get 1280x720 videos to play on my N900 using mpalyer. But it is painfully slow. About 3-5 fps with my overclocked 1Ghz N900. Sound is fine but video is non-watchable and out of sync. Wish mplayer used the DSP. Then it may be able to play most HD files.