Rick Wagoner has agreed to step down as CEO of General Motors. BusinessWeek’s Detroit bureau chief David Welch confirms that after eight tumultuous years of running the largest automaker, Wagoner will take the fall as the federal government prepares to extend more billions of taxpayer money to keep GM (and Chrysler) afloat. Wagoner, 56, had previous denied he would step down, and he resisted efforts to push GM into bankruptcy reorganization. But it looks like his is the scalp that must be offered up to ensure that unions, debt holders, and others will make the sacrifices the Obama auto team is demanding. The Obama team is scheduled to talk about new loans for the automakers, and its demands for more cost reductions, on Monday.