I got on almost immediately, because it worked for me.
Yesterday, I quickly dumped my entire music library into the Amazon "cloud drive". I also downloaded the Amazon MP3 player for my Android device. I am not being paid a cent to say this: I love it. The service has two parts.
The Cloud Player
Its basically like iTunes. The difference being that iTunes is a HUGE program that takes a long time to load. My biggest problem with iTunes is the moment it is on a computer, everything moves slower. Even
high powered Macs start chugging harder when you bring up iTunes. Part of the reason is Apple's graphical (uneccessary) flourishes, but most of the reason is you probably have several GB of music and videos on your computer all in that one place.
With the cloud player, its all in your browser. If you have Chrome, Firefox (or Minesweeper which is the fastest browser I have ever seen), you will be able to access the cloud player amazingly fast.
The Android App
This is where this application really shines. If you have an Android phone, there is absolutely no reason to have this service. You upload your files to the Cloud Drive, and then when you sign in on the Amazon MP3 app, you can play all of your songs in the cloud player. Its an amazing program. I have a lot of stuff going on right now, so I walk around my house with my bluetooth headset and listen to podcasts on the cloud player. I have my phone connected to my Wifi inside, but there were several times yesterday that I had to leave the house and run errands. Every time when I got out of Wifi range, the player contined to work with no interruption in the audio stream.
The switching of networks have ALWAYS been a huge issue in the world of mobile streams, so its very nice to see they worked this out.