How you look at photos. I feel it lacks important features such as zoom (unless you go in to edit it).
And the music player does work, as well as it should that is. But I would like a way for better organization.
And I guess you haven't expired your demos yet, I don't know why Nintendo limits your demo plays. Though it does make me want to buy the games more I guess.
And if it had a video player that didn't automatically delete videos whenever they want to it'd be great. As well as support for videos from your PC.
To be honest, the video player is a waste of time. It records such low quality videos.
That, and video support from the PC would be alright, I guess, if they improved the video player.
Thing is, the 3DS tries to be 90% game console, and 10% media device.
It's an amazing game console, not so hot as a media device.