Well, I think the author is right about professional experience being a bigger factor in hiring than the MA or PhD alone. Even though I have an MA and believe it made me a better qualified candidate than before I had it, ultimately, it is usually listed only as a preferred qualification on job postings. Some level of experience, on the other hand is nearly always a required qualification, and without that experience a second masters or a PhD mean very little.

I disagree, though, with the author's assertion that the lack of an advanced degree will "wreck havoc" on collections. My second degree isn't in the areas for which I collect, but I'd still like to think I do a good job collecting for them. Even if I did collect in history (my MA area), I would still have as much to learn about certain aspects of it - like all non-U.S. history - as someone without a degree. Earning the MA was undeniably valuable in teaching me about the research process, but the content I learned will eventually be replaced with newer ideas. It is reading the book reviews, scanning the literature, and talking with scholars in a particular field that allow a librarian to maintain a current and useful collection, and while a subject degree can give someone a head start with understanding a field, it is by no means the only way to be a good subject librarian.