Internal collaboration within libraries would seem to depend upon the culture of the particular library. A library that is open to change and is comfortable with introducing new technologies would be more likely to succeed than a library where change is a complicated process and where the librarians do not like to use new technologies.
Introducing something like a wiki to a library would not only depend upon a culture that was comfortable with change, but also upon a culture that had a certain amount of trust amongst its members. The nature of a wiki allows for editing by several people. With community driven social software like wikis, lack of trust may mean the difference between a successful wiki rich with content, and one that is not updated and underutilized.
Before implementing a wiki a library should evaluate the strengths and weaknesses of the library and staff. Would a wiki be relevant for the needs of the particular library? Will the staff use the new software? Are they comfortable with new technologies? Does staff collaborate willingly on other projects? If the answer to any of those questions is no, then software like wikis may not be a practical thing to implement.