The Journal has an intriguing quote in its next-day story:
The [administration] auto team prepared briefs for Mr. Obama on his options, as well as viability reports on both companies. The car team wanted an executive who could accelerate the changes it desired. Mr. Wagoner didn't have any support within the group. "This is Obama, and symbols of change are important," said one person familiar with the situation.
Tough to say where the quote comes from. As written, it reads like it's supposed to be an Obama official. But, given the sourcing (and the sentiment), there's no reason it couldn't be a bitter auto-industry official or one of the industry's defenders on the Hill.
Update: The Times has a similar quote from Sen. Carl Levin in its write-up for Tuesday:
Senator Levin said the lawmakers, while saddened, did not challenge the president [on the decision to oust Wagoner].
“He had made the decision that this kind of change was necessary to kind of signal to the public that there was going to be a real effort to make a fresh start,” Mr. Levin said. “There wasn’t much point in arguing whether or not it was fair or unfair, wise or unwise. It was a decision that he didn’t ask us about, he informed us of.”