MacRumors.com

Now available via Software Update:

With iTunes 7.4, sync your favorite music and more with the new iPod nano (third generation), iPod classic, and iPod touch, plus create custom ringtones exclusively for iPhone with many of your favorite songs purchased from the iTunes Store. You can now also play purchased videos with closed captioning (when available), easily rate your favorite albums from one to five stars, and watch videos at a larger size inside the iTunes window.

The update weighs in at 38.5MB and is also available for download at http://www.apple.com/itunes/download/.

It appears to break the simple free ringtone workaround. New workaround posted at iPhone blog.