This study of the North American MARC records market, commissioned by the Library of Congress, is pretty interesting. An excerpt:
…for the moment MARC remains central for libraries. In large measure this is due to the installed base of library systems, which expect and work well with this data exchange format. This will continue to be true until the next generation of discovery and inventory systems are in place. But its limitations are increasingly clear. […] This will undoubtedly change over time, but for now, most libraries will continue to need cataloging records delivered in MARC format—it is the only usable solution.
There remain strong arguments for use of standard cataloging principles‐‐‐controlled vocabulary, classification, subject analysis, and authority control—packaged and delivered in a consistent format. While MARC records may need to be extended, embellished (supplemented with full text, flap copy, excerpts, user tags), for now they provide a common standard and a cooperative infrastructure that controls costs. In the long term, there may emerge better solutions. For at least the next 5‐10 years, however, continued savings can be realized by improvements to the production and distribution systems for cataloging records.
I especially liked the diagram on page 32 depicting the traditional and non-traditional “tiers” of organizations involved in the larger information resource market.
Fischer, Ruth, & Lugg, Rick. Study of the North American MARC Records Marketplace. Washington, DC: Library of Congress, October 2009.