Catholic University's School of Library and Information Science offers a joint program leading to an MLS and an MA in Greek and Latin. No fair! In fact their SLIS offers quite a few MLS/MA combinations, including Law, History, Biology, Musicology, English, and Religious Studies. Of course I was limited by geography to Simmons, the only library school in the state and one of a handful in New England, but I'm pleasantly surprised to see that many institutions recognize the value of a joint degree and the specialized subject training such a course of study can provide.
This idea is explored at length in Reading and the Reference Librarian, by Juris Dilevko and Lisa Gottlieb, a book I picked up over the holidays to linger over in my free time. The authors are of course primarily concerned with the broader picture of how librarians who actively and voraciously read both on and off the job tend to offer better reference services than those who don't in leaps and bounds.
However, they also discuss the relationship between academic reference librarians and the faculty and students whom they serve, finding (not surprisingly) that in order to thrive in a university settings reference librarians must acquire as much subject knowledge - formal or informal - as possible. The ideal is for the academic reference librarian to be a scholar in his or her own right, a colleague of the faculty who takes an active interest in recent developments, academic research, and publication in the fields the library serves.
To this end, joint graduate programs such as those at Catholic University and my own at Simmons are perfect training for academia. The idea of becoming a scholar/librarian has always been for me a large part of the allure of library school, but I'm glad to read that perhaps for the very first time in my life I'm on the cutting edge of a trend and not a few steps behind it!