Quotes from many sources. A particularly good source of quotes on this theme is: The Experts Speak: The Definitive Compendium of Authoritative Misinformation by Christopher Cerf and Victor Navasky (Pantheon Books, 1984).
This started out as a list of negative and pessimistic comments about new ideas, but, to provide some balance, I've begun to add a few overly enthusiastic and optimistic comments.