All the hype in yesterday's announcements was around ringtones and the new Touch ipods. For rating junkies there is now an album rating feature.
Albums have a 0-5 star rating that by default appears to be an average of the ratings on the tracks on the album. You can also manually set the rating.
In smart playlists you can now also select all the tracks for an album based on the Album Rating. If you have a smaller capacity ipod you could start to auto manage the albums that are downloaded by selecting something like
Album Rating > 3 star
My Rating > 3
Limit By x Gb
This will pull in the whole album when you like loads of the tracks, and just individual tracks when you don't think much of the rest of the album