Update: America's Families First Action Fund, an independent expenditure committee associated with a 501(c)4 organization that doesn't have to disclose its donors, discloses its donors. Their plan to avoid 1994 in 2010 is here. My sharp eyed colleague Aaron Bycoffe noticed this in the document the Times acquired: "The project team has established both a federal independent expenditure committee, America's Families First Action Fund (AFFAF) and a 501c4 advocacy organization, America's Families First. Gifts to the independent expentiture committee are disclosed but can be unlimited. Gifts to a 501c4 advocacy organization can be anonymous."

You can't tell the players without the Internal Revenue Code, campaign finance laws, and whole lot of patience.