One blog points out that Apple's iTunes Music store now appears to offer the ability to sell videos as well as songs.
This takes advantage of iTunes new features allowing it to manage and play video files.
This feature is demonstrated in the Feel Good Inc single which was used in the most recent iPod Ad (Rollerskating).
The videos for this particular artist are provided with the album purchase only and are not available for individual purchase. Purchasing the album provides you with 4 short .mp4 videos. These particular videos are 480x272 pixels, 30FPS with 44kHz audio
[Ed note: the videos aren't very exciting or good, imo. Not really worth a purchase]