The Wal-Mart heirs, who make up the world’s richest family by far, are expected to collectively dodge as much as $180.6 million in federal income taxes, thanks to aggressive pursuit of tax benefits set to expire Dec. 31, 2012.

In a move that received little attention due to the Black Friday Strike coverage, the Wal-Mart board announced Nov. 19 that it will rush payment of its quarterly dividend, giving shareholders their bonuses on Dec. 27, instead of Jan. 2 as previously scheduled, reports the New York Times.

The date change means the Walton family (who together own 48% of Wal-Mart) and other shareholders will claim those earnings at the current dividends tax rate of 15%.

The Walton family’s 2012 take of the pie is estimated at a combined $636 million. After taxes, the Walton family should net $540.6 million from the Dec. 27 payment, saving the family $180.6 million over paying the taxes next year as scheduled (based on figures tax attorney Kenneth K. Bezozo supplied to the New York Times).

  If Obama gets his way and the Bush Tax Cuts for the rich expire by Dec. 31, the income/dividends tax rate for wealthy individuals will reset to the pre-Bush-era level of 39.6%. In addition, the health reform bill is partially supported by an additional 3.8% tax on investment income, nudging the total potential tax rate for the wealthy to 43.4%, which is 28.4% higher than the current dividends rate.