Amazon.com just opened their DRM-free music download store "amazon mp3" to public. Actually, I was not aware that it opened today, 9/25. It just so happened that when I took a look, it was public beta.
Anyways, it's still beta and it's been only one day, so we'll have to see for a little more while how this turns out to be. I haven't tried it other then browsing around few pages on their website. The pricing is not as simple as iTunes. Although being cheaper is probably not a problem; many tracks are 89 cents.
Now, will I use this store? Probably. It's DRM-free MP3, works with iTunes and other Apple products, most likely to be cheaper than iTunes and just because I know how to add MP3 files to my iTunes library. Will this be my primary store? Probably not. iTunes is just so simple, easy and convenient and humans are so lazy; I think it's hard to beat iTunes by this means. And if you want ringtones for your iPhone, you will need to purchase those tracks on iTunes.
BTW, one thing I thought was funny. The most popular track on amazonmp3 as of now is "1234" by Feist. This music is actually used for the latest iPod nano ad. I don't think this is just a coincidence...