The point of the second suggestion was not to devalue old
nodes, but rather to help people searching the archives
judge which answers to a question are the best - if you
don't know about a subject, you will have difficulty telling the difference between a good answer and a great answer - though I imagine the really bad answers will tend to speak for themselves (or have helpful followups)
It would just be a helpful cue to people who are new here or who are new to a subject as to which answers in the archives are the best or most helpful (or at least, those that other people think are the best or most helpful :-)
Andrew.