There is a Sakai discussion group focused on digital library related matters, which has focused on two major areas of interest: finding ways of exposing library resources and services through Sakai, including integration with library systems such as electronic reserves and library catalog, and connectivity to digital repositories, which may be library repositories, institutional repositories, or other types. 

During the most recent Sakai conference, there were several sessions led by members of the library community that focused on these topics and other topics like standardized interfaces which might enable users to access and store content in various repositories using tools within Sakai.  The Sakai community is seeking greater input and involvement from the library community, so I hope you'll consider attending the upcoming conference.  Further information about the Sakai conference is available at:

Sayeed