I agree with those who suggest that the original Save As implementation wasn't entirely intuitive. But it was what we were used to and to restore the name of a command with that kind of history but change its functionality is curious to me.
So, other than choosing to revert the document via the Time Machine interface, is there some other way to approximate the Save As behavior of old? Not in as few steps, regrettably. Try this:
Launch System Preferences and in the General preference enable the Ask To Keep Changes When Closing Documents option. Close System Preferences. Launch the application you want to work with and do something. Save the document. Edit your document and add more content--delete some words and add a couple of paragraphs, for example. Choose File -> Duplicate (Shift-Command-S). You will now have two identical documents open. Close the original document. Because of the option you enabled in the General system preference you'll be offered the option to revert your changes, thus giving you a saved version of the original copy.
Fine, fine, another spittle break.
So, what we're after is a single command that invokes these steps: Duplicate, Close, and Revert Changes. AppleScript might be an option, but not all applications are scriptable (Preview, for example). I've solved the problem by turning to Stairways Software's $36 Keyboard Maestro. This is a fine macro utility (remember those?) that allows you to trigger a gang of actions with a single keystroke.
Specifically, I created a macro that performs the following actions:
Type Shift-Command-S (to invoke Duplicate)
Type Return (to accept the name of the copy in the title bar--My Document Copy, for example)
Type Command-` (to switch to the original file's window)
Type Command-W (to close the original window)
Press Button 'Revert Changes' (to revert the original document to the point of the last save)
Yes, it's a $36 solution to what shouldn't have been a problem in the first place, but it works with any application that supports Mountain Lion's new Save As implementation.
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