I will agree with the points made about announcing older obsolete machines might actually be a good idea in the sense they are more than likely headed for the scrap pile if they don't sell, and very few people are actually interestd in the purchase of them.

But announcing more popular and more modern items, esp in areas where the pieces will go for big $$ (like the Wash DC area), I think is where the line has to be drawn. Its not real clear where exactly that line has to be drawn. I think its best to think about the given situation of the particular auction, and the ramifications of announcing it or not announcing it. I think in most cases the person who announces it means quite well, but is not fully cognizant of the ramifications (to others) his announcement will make - especially when said announcer will not even be part of the auction.