Forbes:  “Lawyers see litigation and administrative nightmares resulting from political impasse.  Barring a last-minute political deal, the federal estate tax is set to disappear as of Jan. 1, 2010–for just one year. Democratic leaders of Congress are vowing to resurrect the tax retroactively sometime next year, but the impending lapse has estate planners in a tizzy. They worry the lapse could turn into a nightmare for some families.  ‘We may have to change every other client document,' laments Carol Harrington, the head of the Private Client Group at McDermott Will & Emery.