The Citizens for Tax Justice have a good article advocating acceptance of the Buffet Rule--along with a switch to treating investment income like any other income.
[Excerpt] The most straightforward way to implement the Buffett Rule would be to eliminate the personal income tax preferences for investment income. This would mean, first, allowing the parts of the Bush tax cuts that expanded those preferences to expire. Second, Congress would repeal the remaining preference for capital gains income, which would raise $533 billion over a decade. When President George W. Bush took office, the top tax rate on long-term capital gains was 20 percent, and the tax changes he signed into law in 2003 reduced that top rate to 15 percent. The same law also applied the lower capital gains rates to stock dividends, which previously were taxed as ordinary income. If the Bush tax cuts, which were extended through 2012, are allowed to expire, then capital gains will again be taxed at a top income tax rate of 20 percent (meaning there will still be a tax preference for capital gains) and stock dividends will once again be taxed like any other type of income.