A while back we noted that Amazon was planning to bring its video on demand service to the Mac. Well, it looks like they've finally flipped the switch because the service is now live.
Much like iTunes, they're selling TV shows as well as offering movies for purchase and rent. Unlike iTunes, it's a streaming rather than a download service. Fortunately, they've got a number of free videos which will give you a sense of the quality of the service (which requires Flash).
Frankly, I'm a big fan of Amazon MP3, so it's good to see Amazon getting into the video business as well to put a little more competitive pressure on iTunes. I'm doubtful, however, that it will really affect the iTunes juggernaut.