Jeffrey Owens (Director, OECD Centre for Tax Policy and Administration) has published Abusive Tax Shelters:  Weapons of Tax Destruction?, 40 Tax Notes Int’l 873 (Dec. 5, 2005), also available on the Tax Analysts web site as Doc 2005-22843, 2005 WTD 234-6.  Here is the Conclusion:

The robust actions by some OECD governments, combined with an increased awareness of the financial and reputational risks associated with aggressive tax planning, have led many corporations and the tax advisory community to become more risk-adverse in their tax strategies. CEOs and corporate boards are beginning to take responsibility for their tax strategies and to reassess the potential risks associated with those strategies. An increasing number of companies are including explicit requirements in their tax policy strategies to comply with overall sound business principles and are involving corporate governance experts in their discussions on taxation. These changes in attitude suggest that governments were right to respond aggressively to the threat of tax shelters and that we will see many other countries following the United States’ lead.