State Estate Tax Changes    The Wills, Trusts, and Estates Prof Blog reports that the federal estate tax exemption was indexed for 2012, increasing the $5 million exemption to $5.12 million. Many of the twenty-three states, including Washington, D.C., that impose state estate taxes have also made changes for 2012. A list of state specific changes to estate taxes for 2012 and beyond is below: To keep up with ...