Mountain Lion's Save As isn't what it once was

08.08.2012

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.