iCloud seems to be just what John Gruber predicted: a total replacement for iTunes. We’ve already heard that iOS 5 will be “cutting the cord” for the iPhone and iPad, and iCloud seems intent on furthering that idea.
Everything seems to be synced to the cloud, and pushed back down. For example, a calendar event could be added on the iPhone, and it should appear on the iPad, the Mac (via iCal), and any other Apple connected device you own. The cool thing is that it seems like Apple has included iCloud in basically every aspect of iOS 5, from the App Store to the new Reminders app. Backup is also included, in that once a day a lot of “important content” is backed up to the cloud. For any new device you get, everything will be automagically synced back down. It only works over WiFi, though.
Pages’ documents will also be stored in the “cloud,” along with other formats that you create in the iWorks suite.
Oh, and MobileMe? It’s free, starting today. Go crazy!