In order to add the Photo syncing capability to the new “Photo iPod”:http://forevergeek.com/apple/apple_photo_ipod.php, Apple had to update iTunes to version 4.7, which includes a couple of features other than the photo-syncing capability.
The new version also now helps manage large libraries by searching for and deleting duplicate songs in your library. Helpful if you’ve ripped a few CD’s twice, or downloaded a song a few times from differenty web sites or P2P apps.
The other new feature is an “artist alert” that will tell you when something new is added to the iTMS by your favorite artist. I’m not sure how they know who your favorite artist is, maybe it’s based on ratings, or play counts.
iTunes knows about artist because artist alert
available from the artist dedicated page
You add as many “favorite artists” as you want via links in the iTMS. There is also a checkbox to add all artists that you’ve bought music from.