Amazon, Google, and Apple are simultaneously coming out with a new service: your music in the cloud so you can play it anywhere. (Apple will even scan-and-match so you don't have to upload most of it.)
I'm not sure I get why it's such a big deal? Don't people have iPods? My classic iPod holds all the music I have collected through 20 years, with 30% still left to go before it's full. It can sit in any pocket I have, so why do I need to have my music sit in the cloud?
I like many of the other iCloud things, like simultaneous/automatic sharing of content and apps to all your devices (You take a photo, and a minute later it's on your computer too), but the music thing... could be handy in some situations, but important? I dunno.