Apple's patented the obvious and the expected: a way to store and stream your iTunes library from the cloud. But there's one weird twist—the option to only partially push your media up to the sky. Huh
The "partial sync" option takes a sliver of each song and keeps it on your iPhone or iPod (or whatever)—with the rest of the track hosted cloud-side. The point here, it's assumed, is to preclude the need to buffer the start of each track, so that the cloud experience doesn't feel like a cloud experience. And given 3G data speeds, that'll probably be a good thing.
But is partial cloud hosting real cloud hosting? No. The whole point of the cloud utopia is to eschew physical storage, so that everything we want to listen to, watch, and read, is spirited away to a remote server fairy world. Not a cache on your phone. But it's only an option—presumably you'll be able to sling your library to Apple's storage world en masse, with no local snippets.
The patent also (surprise!) provides a variety of ways to keep out unauthorized streaming, so that everyone you know doesn't piggyback off your library and give every record label exec a heart attack.
Now, patents are just patents—they exist on paper, not on shelves. So don't assume you'll see this method in its entirety (or at all)—but it's not too far fetched to expect something very close. [Patently Apple via Cult of Mac]