A half-dozen Am Law 100 firms—Cadwalader, Wickersham & Taft; DLA Piper; Haynes and Boone; Latham & Watkins; Perkins Coie and Squire Patton Boggs—have new leaders in place with the start of 2015. As they begin their first full week of work in their official roles, the new chairs and managing partners are sketching out strategies for their first 100 days and trying to fill the shoes of former leaders.

Their predecessors, however, have a whole different set of challenges: getting out of the way of new management and filling up suddenly open calendars. Two have already left their firms.