Even better, once iTunes Match has "matched" those tracks, it replaces low-bit rate versions with 256-kbps, DRM-free AAC versions. For the songs iTunes doesn't offer (Apple says it currently has 19 million tracks) you can upload your own files instead. Apple says that you can store up to 25,000 matched and manually-uploaded tracks -- iTunes-purchased tracks don't count against this limit. For those with really big iTunes libraries, we don't know how you'll decide which tracks and albums you want access too. Also, it's unclear what happens when you stop paying the annual subscription fee, but if it's anything like other subscription music services, chances are that a portion of your iCloud experience will cease to function.
If I don't renew iTunes Match after a year, do I lose all of those non-iTunes songs I downloaded to my devices?
We don't know. If we had to guess, we'd say you probably get to keep those files forever, but when your subscription lapses, you will no longer have access to them on iCloud, so you won't be able to download them to any device on demand. We're guardedly optimistic that the music files themselves will remain intact and playable, but detached from the cloud.
Does it work with any other purchased files?
Yes, you can set up your iOS devices to auto-download newly purchased apps and books as well.
What about other iTunes Store content, like movies and podcasts?
At this point, it looks like the iTunes in the Cloud features are limited to music/apps/books, so no TV shows, movies, podcasts, or iTunes U content downloaded from the iTunes Store. That could be due, in the case of movies and TV shows, to concerns about bandwidth and/or licensing agreements with studios. But we suspect Apple will extend iTunes in the Cloud to at least some other types of content at some point.
Can I use iCloud to back up my iOS device?
Another aspect of iCloud is automatic data backup. According to Apple, once a day -- but only when your iOS device is connected to both a power source and a Wi-Fi network -- iCloud will back up many types of user data to the cloud. It won't back up everything, but it will handle purchased music, apps, and books; your Camera Roll (photos and videos); device settings; app data; Home-screen and app organization; text and MMS messages; and ringtones. If you ever get a new iOS device or need to restore from a backup, Apple said, you can just enter your Apple ID and password and everything will be automatically loaded onto that device.
Will I be able to use iCloud to sync settings and other data between my Macs?
Other than the types of data already mentioned -- photos, media, and data in iCloud-enabled applications -- Apple hasn't said much. But we think it's only a matter of time before you'll be able to sync, say, your application and system settings, and perhaps even your login sessions, between your Macs.