> On the other hand, as more libraries get into the business of publishing, 

> they may need more staff!  

To Joe’s question, though, I think the question here is not so much whether libraries would need more staff in order to sustain publishing operations, but rather how much the libraries’ host institutions want them to be publishers. Where the university strongly favors that direction, I think the library’s budget will stay strong even if the cost of access to scholarship were to become effectively nil. But wherever the ultimate source of an academic library’s funding is the institution it serves, it won’t be purely up to the library whether or not it develops a robust publishing program.

(Anticipating one possible response, I’ll preemptively point out here that moving the university press into the library is not necessarily the same thing as encouraging the library to develop a library-based publishing program—especially if the UP comes without any additional institutional subvention. In some cases it may just reflect the institution’s desire to move one cost center under the umbrella of another one.)