iTunes got a serious overhaul today. Apple introduced new features that use iCloud to save where you stopped on a tune, movie or playlist to allow you resume on another device, browse via albums in the iTunes store and access artist information from your currently-playing msterial. iTunes also picked up an updated mini-player that looks sharp and fits in the corner of your screen and lets you search your library and control playback at any time.
Adding songs to a playlist is much easier than before, and you can see songs in your playlists and your library at the same time. You can click an album or song in-place to expand it and see details about the song or artist (similar to the way folders expand open in iOS.)
Apple has integrated Facebook with iTunes (most probably at the expense of Ping) so you can share the songs you're buying or listening to. The new design makes the desktop versions of iTunes much more like the iOS version, which we can only hope means faster performance and less bloat overall. The new iTunes will be available for OS X and Windows in late October.