It seems that SEIU is close to endorsing Edwards. According to this Bloomberg story, he has more support than any other candidate, although not yet enough to put him over the top. From the article:
John Edwards has more support from Service Employees International Union members than any other presidential candidate, though not enough yet for an endorsement, said Andy Stern, president of one of the largest U.S. labor groups.
About 2,000 of the union's leaders will meet Sept. 17 in Washington to listen to pitches from the major Democratic candidates and take a straw poll that will help guide the group's endorsement, Stern, 56, said in an interview.
This would be a major milestone for Edwards, especially after already garnering the endorsements of The Transport Workers Union of America (TWU), The United Brotherhood of Carpenters and Joiners of America, The United Steelworkers (USW), and the United Mine Workers of America (UMWA).
Stern also mentioned Hillary and her union-busting strategist, Mark Penn:
Stern also said he spoke to Clinton's campaign aides about Mark Penn, her top campaign strategist, who has been criticized by labor officials. Penn, chief executive officer of the New York-based public-relations firm Burson-Marsteller, should "stop taking any clients in his business that are anti-union," Stern said.
However...
He stopped short of saying that Clinton's association with Penn would prevent SEIU from backing her.
Considering Edwards' strong support of unions, my bet is he'll get it...but we'll see.