It would be really nice to have a "Fit to Pages..." command in Word that
would bring up a dialog where I could specify a number of pages (such as 5)
and click checkboxes to specify what can be adjusted:  e.g., [] Font sizes,
[] Margins, [] Line spacing.  Then Word would automatically adjust the
document content as needed to fit within the specified number of pages, while
leaving alone whatever is unchecked.  If the user doesn't like the results,
she should be able to Undo and try again with a different combination of
scaling options.  There should also be an option "[] Keep adjusting while I
edit" so that if I type more content, the existing content is adjusted as
needed so the document remains within the specified page limit.
    There is already a somewhat similar feature to fit on a certain number
of pages when printing in Excel, and even Powerpoint has text boxes that
automatically adjust the font size of their content to fit on the slide.  
This seems like a natural feature for Word, as many users are given
requirements that their document should fit on a certain number of pages.