iayork linked to this silly New York Times article on people anthropomorphizing their iPods' shuffle function. Toward the end it vaguely mentions Smart Playlists as an alternative.

I almost never use the iPod Shuffle on my entire song library because large chunks of it are multi-movement classical pieces whose movements don't always work well in isolation. I'm much more likely to shuffle either a Smart Playlist or a manually assembled playlist.

The iPod makes a game attempt to replicate iTunes' live updating of Smart Playlists based on play counts. Unfortunately, I think I've found a bug. I have a Smart Playlist called "Not Recently Played" that just collects the tracks that were last played the longest time ago. I listen to it when I want to hear something I'm not bored of. In iTunes it works fine. On the iPod, though, as you listen to music, sometimes it starts accumulating the tracks that were played the shortest time ago, instead (which is a whole other Smart Playlist). The playlist only recovers its senses when the iPod syncs up. I haven't done enough experiments to characterize this behavior precisely.

Also, I want the iPod to have more of iTunes' host-based software features, though admittedly it would be difficult to design user interfaces for them. Ian's into writing elaborate scripts for custom shuffling methods, but as I've said before, I'd really like to have something like iTunes' Party Shuffle (a shuffle-play mode that allows preview and manual editing of the shuffle queue).

What I miss even more on the iPod is the ability to re-sort a playlist by various criteria. The iPod seems to retain the sort order that you had in iTunes the last time you synced, which is reasonable; but iTunes makes it so easy to re-sort by some piece of metadata just by clicking on the head of its column (one of my favorites is track length, for when my attention span gets short) that it can be easy to forget that you can't do it on the iPod. Besides which, it's not very smart about sorting Smart Playlists that are updated live; I think it just tacks the new tracks on the end.