Personally what I wish they would do but never will is this:
When you are scrolling through your various items be they playlists, songs, artists, albums, etc you never know what rating you have given said playlists, songs, artists, albums, etc. At least on the iPod you dont. What I would like to see is Apple go to a color coded star system:
1-Black
2-Red
3-Orange
4-Yellow
5-Blue
So lets say you are scrolling through your albums list. iTunes desktop client averages out what your rating for that album and color codes it appropriately. So when you scroll through the list you know HEY! I really like those songs in that playlist because its got a yellow color to it. Or I really like that album because its Blue. Apple could do so much with color in the iPod Photo beyond simply viewing pictures. It just kills me that they havent done anything with the interface. Hello!! *knock knock* Hello in there Apple. Its called innovation.