An interesting report called The Changing Nature of the Catalog and its Integration with Other Discovery Tools written by Karen Calhoun, of Cornell University Library, and commissioned by the Library of Congress is now available on the web.
Here is a small excerpt from the summary:
The destabilizing influences of the Web, widespread ownership of personal computers, and rising computer literacy have created an era of discontinuous change in research libraries at a time when the cumulated assets of the past do not guarantee future success. The library catalog is such an asset. Today, a large and growing number of students and scholars routinely bypass library catalogs in favor of other discovery tools, and the catalog represents a shrinking proportion of the universe of scholarly information. The catalog is in decline, its processes and structures are unsustainable, and change needs to be swift.
Calhoun raises a number of really excellent points, highlights problems with catalogues and proposes a number of solutions.