OCLC's Lorcan Dempsey, by way of his blog, provides us with a  useful set of ruminations about how to think about the future of the library catalog, and a framework for asking that question in a broader context. Along the way, he also places a number of other library services (Interlibrary Loan, Federated Search) into that framework, providing useful ways to think about all of the evolutions implicated in the suprisingly rapid transition to a more fully networked information system.  On the catalog, he writes: