The Digital Library Collections Task Force Report, from August 2009, includes the following recommendation:
Principle No. 9, Digital Format Preferred: For journals that are available in both online and print, the Library purchases the online version, with exceptions made when print is necessary.
Collections Council has recently endorsed this recommendation and approved a set of guidelines that helps to identify when print is necessary. These guidelines can be found at:
http://www.lib.berkeley.edu/Staff/CDP/purchasing_print_journals.doc
Please send any questions to me at bhurley@library.berkeley.edu
Bernie