Michael W. Peregrine (McDermott Will & Emery, Chicago) & James R. Schwartz (Manatt Phelps & Phillips, Los Angeles) have published Director Recruitment and Retention in a Post-Sarbanes World, also available on the Tax Analysts web site as Doc 2005-3003, 2005 TNT 62-37.  Here is the Introduction:

It’s becoming a seller’s market. The recruitment and retention of qualified directors will be one of the most significant governance challenges for the nonprofit corporation in the post-Sarbanes/Oxley world. The ability and willingness of the volunteer director to serve is increasingly being tempered by concerns such as personal liability exposure, increased workload, and appropriate limitations on charity board membership. Given these understandable concerns, nonprofit organizations must be pro-active in order to attract competent director candidates, and to convince experienced directors to continue their service. Make no mistake about it — these individuals will have board service choices. Fortunately, the law offers a variety of means available to nonprofit corporations in their governing board recruitment and retention efforts.