There are other iCloud related changes in Mountain Lion that may affect your preferences, but that are
not affected by the changes made to iTunes settings suggested by Ganbustein. In the
Bugs and Fixes topic
Default folder changes in Mountain Lion Ted Landau discusses the fact that certain new documents get saved to iCloud by default in Mountain Lion. The new default setting cannot be permanently changed other than by unchecking
Documents & Data in iCloud’s System Preferences. This behavior is currently shown by TextEdit and Preview, as well as certain 3rd party apps, but will presumably be extended to other apps as well.
