Prior to iCloud, it was necessary to explicitly encrypt iOS device backups in order to include passwords stored in the iOS Keychain. Indeed, this was an important and recommended use of encryption, which allowed easy migration from device to device without having to reenter passwords, but it us unclear whether iCloud backups behave the same way. In fact, it's difficult to tell from the layout the settings UI in iTunes whether encryption applies only to local backups, or to those iCloud backups as well (though the former seems to be the case):
Are iCloud backups of iOS devices encrypted by default? Do they store iOS Keychains, so that after a restore of an iOS device from an iCloud backup, all saved passwords are available there?