Reviews the historical context of core journal lists, current uses in collection assessment, and existing methodologies for creating lists. Outlines two next generation core list projects developing new methodologies and integrating novel information/data sources to improve precision: a national-level core psychology list and the other a local institutional core list for the interdisciplinary field of urban studies and planning. The paper is based on the authors' panel presentation at the 2009 ACRL National Conference (Seattle, Washington) titled "Core Journal Lists Re-viewed and Re-imagined." (Contains 1 figure.)