This excerpt taken from the NKE 10-K filed Jul 27, 2009.
Changes in tax laws and unanticipated tax liabilities could adversely affect our effective income tax rate and profitability.
We are subject to income taxes in the United States and numerous foreign jurisdictions. Our effective income tax rate in the future could be adversely affected by a number of factors, including: changes in the mix of earnings in countries with differing statutory tax rates, changes in the valuation of deferred tax assets and liabilities, changes in tax laws, the outcome of income tax audits in various jurisdictions around the world, and any repatriation of non-US earnings for which we have not previously provided for U.S. taxes. We regularly assess all of these matters to determine the adequacy of our tax provision, which is subject to significant discretion. Recently, the Obama administration proposed legislation that would change how U.S. multinational corporations are taxed on their foreign income. If such legislation is enacted, it may have a material adverse impact to our tax rate and in turn, our profitability.