Jon Kingsdale, head of the quasi-Massachusetts agency that oversees the state's landmark health law, is stepping down June 4, Governor Deval Patrick announced. Kingsdale said in an interview with the Boston Globe that he has not yet decided on his next step, but is interested in working on implementation of the national healthcare overhaul that was in large measure modeled on the Massachusetts law. He said he had spoken with the Obama administration, but for now has decided against taking a job in the federal government.