Music - as long as they MP3, AAC or WAV(? it does WAV doesn't it?) then yes.
Video - less likely to play what you already have out of the box. It accepts MP4/h264 only. If you are like me and have a mountain of DivX and Xvid then you'd be looking at an awful lot of video conversion to make them play. (Which is a shame. If they finally brought those formats on board I may actually have looked at one myself.)
Pictures - no idea .... I'd expect so.
The Apple website will have details of this in the specs for the touch.