It looks like Fritz Henderson, who only took over as GM's CEO back in March, has been forced out by the company's board. From the Times:

General Motors said Tuesday that its chief executive, Fritz Henderson, was resigning and would be succeeded on an interim basis by the automaker’s new chairman, Edward E. Whitacre Jr. ...

Mr. Henderson became chief of G.M. after the previous chief executive, Rick Wagoner, was asked to resign in March by President Obama’s auto task force. But in a sign that the company’s board is dissatisfied with G.M.’s progress, Mr. Whitacre, the retired head of AT&T, will assume the top job on a temporary basis.

“We all agreed that some changes needed to be made going forward,” Mr. Whitacre said.

It's obviously a little early to draw conclusions about what happened. But my first impression is that this could be a signal of relative strength. When the Obama auto task force fired Wagoner, it seemed to want to replace him with an outsider capable of shaking up the company's staid culture. But the task force worried about putting the company through such a radical change during a period that was already so wrenching, and so it settled for Henderson. At least that's the impression you get from former auto czar Steve Rattner's account in Fortune last month. And from this excellent narrative of the GM bailout in the Times back in July. The Times piece actually had a great nugget highlighting the cultural problem Henderson posed:

In truth, the task force had no interest in running G.M. But the only available alternative to Mr. Wagoner was Mr. Henderson, a lifelong G.M. employee, and he did not initially impress some task force members, according to administration officials involved in the discussions.

When asked at an early meeting to discuss G.M.’s culture, he gave what some members of the task force described as a long, meandering answer, concluding: “I’ve been here 25 years. This is the only culture I know.” However, Mr. Henderson quickly added that he was determined to change it.

The panel considered making him an interim chief executive, but decided that G.M. employees, rattled by the financial crisis and the departure of their boss, could not handle more uncertainty.

Again, tough to say exactly what happened so soon after. But my guess is that, after some mildly encouraging third-quarter results, the board thought GM was on sound enough footing to go ahead and make a change they'd wanted to make for months now.