His list of worn-out metaphors understood by few, "ring the changes on, take up the cudgel for, toe the line, ride roughshod over, stand shoulder to shoulder with, play into the hands of, no axe to grind, grist to the mill, fishing in troubled waters, on the order of the day, Achilles' heel, swan song, hotbed" is still apt. "Ring the changes" is misused in today's South China Morning Post.[1] My own favorite is "free rein", which is a horse term. (One not used by riders today; riders say "loose rein".) It often appears today as "free reign".
Today's metaphors come from popular culture rather than the classics, and age faster. This may not be an improvement.
[1] http://www.scmp.com/sport/rugby/article/2002459/mark-coeberg...