Apple released a new version of iTunes that includes iTunes Match ($24.99/year). Its part of Apple’s iCloud service. Music match will scan the content of your iTunes library and match it to the ITMS selection. Music that doesn’t match is uploaded — and you end up with all of your music in the Apple cloud, playable on any iOS or Apple (or even PC) device:
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 iPhone, iPad, iPod touch, Mac, PC, or Apple TV. 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.
Hat tip The Loop