i've done this a few times. i've learned not to get too attachted to any playlists... i lose them every six months or so usually. it doesn't seem to be an exact science, but my suggestion would be find the com.apple.itunes.plist (or similar, look in the library in either the system or your user folder, and navigate through until you find the right file. it's confusing, but quite intuitive if you think about it) and transfer that to your new 'book. that would be all the settings (playlists included)
another option (i've never done this, so can't vouch) would be the old-to-new apple firewire connection transfer facility. it should tranfer EVERYTHING across, so you can sit back and enjoy the speed increase without the hassel of set-up