iTunes 7, announced at today's "It's Showtime" media event, is available for download (requires Quicktime 7.1.3, available here). The "iTunes Music Store" is now referred to as the "iTunes Store".
iTunes has interface changes, as well as new features:
Movies - 640 x 480 px movies you can purchase for download from the iTunes store. Currently, only Disney-affiliated movies (Disney, Pixar, Miramax, Touchstone) are offered, but Jobs promised more to come. More details are available via Apple's site.
Cover Flow - lets you navigate through album art to mimic flipping through a CD collection. details
Free Album Art - automatically fetching of album art for CDs you import (with iTunes account).
iPod Games - $4.99 in the iTunes store. details
iPod Summary - at-a-glance information, including storage allocation. details
TV Show Resolution - TV shows will now be sold at 640x480 px h264. While the updated 5G iPods announced today will be able to play the new format, there has not been any indication from Apple of yet that the new shows will be playable on older 5G iPods. Apple's official knowledge-base article still states that h264-encoded movies must be 320 x 240 at 30 fps.