I don't understand why anyone would want to listen to music on an iPod and have visualizations displayed on the screen! What purpose would that serve, beyond the 5-minute cool factor and a shortened battery life? As for video and photos - with a screen that small, and the resoultion as low as it is, it would be next to pointless to use. Granted, with a higher resolution, colour screen, I could see some uses for it... but again, you're going to kill the battery much quicker. Now, if I could plug a digital video or still camera into an iPod and use it to store/preview images and video... well, then I'd call that progress!
Also, why hasn't Apple made the iPod OS open source, or allowed for plug-ins? Imagine all of the interesting perfierals you could plug into that firewire port!