Gizmodo has an interesting post about IPod's main drawback - the battery. Apparently they only last a year and a half, and Apple charge 225(!!) for a replacement. You can get a whole new player (well, non-IPod) for that. I'm happy I decided against the IPod in favor of one from Creative (which I'll blog about as soon as it arrives).
Edited - So it looks like the situation was a bit overblown. You can get cheaper replacements elsewhere. See some of the comments in the link.