Apple's iCloud music service was rumored to stream media, but it just syncs files.
Apple has unveiled the iCloud on Monday. The iCloud is simply taking care of your data, including music, to be available on all your devices. That is the main overall offering of iCloud. In respect to music, many rumors say Apple to actually enable streaming of music like Amazon and Google offer in their music locker services. Why has Apple not made streaming part of iCloud?
I think to keep things simple. The iCloud needs to be adopted broadly. The overall notion of keeping content up to date across all devices applies to not just music. I think that Apple will release a streaming option once Apple tackles movies in the cloud. iTunes in the cloud is currently just handling music. As soon as Apple also handles TV shows and movies streaming becomes important. Today when I rent a movie directly on the iPad 2, I have to wait until the download is complete. This wait time sucks. Instant streaming would solve that.
Another reason to avoid streaming for now are the carrier networks. High quality streaming eats a lot of bandwith. Many plans are data plans are limited and carriers do not like the idea of all iPhone users out there stream over 3G. Broad adoption of streaming media will require LTE networks.
So for now I think Apple did the right thing to not add streaming to the iCloud.