Bloomberg News has a useful article about all the ways that it would be possible to get around the Buffett Rule if it passed. According to the article, the rule would not apply to income from tax-free municipal bonds, so it would create a much greater incentive to invest in those rather than in stocks or corporate bonds. Also, "Because the Buffett rule would effectively deny the benefits of the state and local tax deduction, it would create a greater-than-usual incentive to move to a state such as Florida with no income tax." Funny, I haven't heard President Obama or Warren Buffett or Whitney Tilson talking much about the tax break on municipal bond interest as they go around making the case for the Buffett Tax.
Getting Around the Buffett Rule