One of the things that Apple mentioned a few months ago is the fact that along with the iCloud system, they would be releasing something called iTunes Match. This is basically a service that will allow you to take your entire music collection with you wherever you as all of your music will be backed up on the cloud and then downloaded whenever your request it. SO far, we have heard little about this but now, it has been released in the latest version of iTunes which is available to developers.
iTunes Match service is working pretty well in the latest developer release of the iTunes software. It is said that the iTunes Match service is now working better than ever and that it also downloads the songs and album art extremely quickly to a users iPhone device.
There are many cool features to the iTunes Match service however and it is said that it does a great job of actually matching your music, which was always a concern.