Pogue does mention it—in a casual aside on page 75—but since the hidden
~/Library debuted in Lion, the lack of prominence is understandable. (Not saying I agree with that, but the hidden
~/Library folder was so widely discussed in the overall Mac internet literature, folks like me had internalized the fact long before actually upgrading.)
As for artie's concern that you may need to change the default save-to-iCloud setting despite your lack of connection to iCloud, I can't say, mostly because I did move to iCloud, and because the source I relied upon more than any other for gaining familiarity with Mountain Lion beforehand—John Siracusa's
OS X 10.8 Mountain Lion: the Ars Technica review—assumes the user is iCloud-connected when he describes the various features and limitations of the integration of iCloud into the operating system. (See
iCloud and you and
iCloud vs. reality for the gory details.)
It should be easy enough to figure out, though: what happens when you go to save a new TextEdit document? (It should be pointed out that this is only an issue for apps written to take advantage of this Save-to-iCloud interface. Among Apple's bundled apps, these are limited, I think, to TextEdit and Preview; I believe the iWorks apps also fall into this category.Third-party adoption of the Save-to-iCloud approach has been somewhat problematic, but I don't have information on specific apps.)
If you find that you are plagued by this and other Mountain Lion "features," but don't feel like searching high and low to find solutions, or using Terminal to implement those which lack a GUI front end, you might check out
Mountain Tweaks, which I haven't used, but which seems to include all the Usual Suspects I've encountered or read about.
