Hixie, haven't you done this work already, a query for bugs with a status with 'Hixie' gives a nearly perfect coverage of the most critical layout bugs.
http://bugzilla.mozilla.org/buglist.cgi?bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&bug_file_loc_type=allwordssubstr&status_whiteboard=hixie&status_whiteboard_type=allwordssubstr Bernd
