Here are a couple of articles - the first from Apple's own website...
Apple - iCloud stores your content and pushes it to your devices.
iTunes in the Cloud
Download your music whenever and wherever you want it.
New purchases. Automatically everywhere.
iCloud automatically downloads any new music purchase to all your devices over Wi-Fi ? or over 3G if you choose. Which means you can buy a song from iTunes on your iPad at home, and find it waiting for you on your iPhone during your morning commute. All without having to sync.
Your past purchases. Available on all your devices.
Now you can download music and TV shows you?ve previously purchased to all your devices. When you buy from iTunes, iCloud stores your purchase history. So you can see what you?ve bought ? no matter which device you bought it on. You can access your purchase history from the iTunes Store on your Mac, PC, iPhone, iPad, or iPod touch. And since you already own the songs, albums, or TV shows in your purchase history, you can tap to download them to any of your devices.
Apple's iCloud Similar To Google's, Amazon's - Peter Kafka - Media - AllThingsD
That's what all the commotion was about when it was announced... that there would be NO music streaming...