Update No. 8 (October 2007) was recently released in multiple document formats. It includes changes made to the MARC 21 formats resulting from proposals which were considered by the ALA ALCTS/LITA/RUSA Machine-Readable Bibliographic Information Committee (MARBI), the Canadian Committee on MARC (CCM) and the BIC Bibliographic Standards Group in 2007.
The printed update is available through the Cataloging Distribution Service.
It includes pages for fields that have been changed, with changes marked with side lining. PDF of those printed update pages are also available online