For a decade, the cataloging world has relied upon the _Anglo-American Cataloging Rules 2nd ed. revised_ to guide its work. As soon as July 2011, AACR2 might be replaced with a new cataloging code, Resource Description & Access (RDA)
RDA is still a work in progress, but this talk covers the main goals in greater detail and points out a couple of the major changes to our MARC records (major new fields and subfields) that appear in records already.
Graham, Suzanne R., "Resource Description & Access" (2011). Presentations. Paper 65.