Rick Anderson's essay stuck with me mainly because of the line:
"...it can be equally disastrous when a profession fails to acknowledge and adapt to radical, fundamental change in the marketplace it serves."
I had recently been to a ConEd class called "Show Me the Money" where the representative from OCLC said something similar, about libraries having to know what business they are in. His example was a typewriter store. If the owner of the typewriter store thought he was in the business of selling typewriters, he was out of business as soon as the word processor was developed. But, if he saw himself in the business of document preparation, or communication, or whatever, he would have realized what the invention of the word processor meant, and shifted to meet customer demand.
I am really roughly paraphrasing here, but that's the basics. So, for libraries, we have to determine what we are really in the business of doing, and keep track of the best ways to fulfill customer demand.