Everyone seems to think it's down to Larry Summers or Tim Geithner. I'd be happy with either, though the left wing of the Democratic Party seems to be gearing up for a hate-fest on Summers. The previous two sentences may, of course, be related.
Economics of Contempt wishes for Geithner, but thinks we'll probably get Summers because now is a lousy time to go switching out the president of the New York Fed. I think this attributes too much sense to politicians, but he may well be right.
Whoever we get--Geithner, Summers, or a dark horse--I think it will have to be someone who's either very risk-loving, or doesn't care about his reputation. I've talked to quite a few smart economists with specialisations in various aspects of the crisis over the last few months, and the conversation usually goes a lot like this.
Megan: So, the financial crisis. What the hell?
Smart economist: Yeah, that's what I'm titling my next paper.
The lack of understanding, much less consensus, on what is happening and what to do next, would seem to indicate that there's a not insignificant chance that the crisis will get worse and the Obama administration will not be able to do anything about it, making them look (unfairly) completely incompetent, and giving generations of future economists something to smugly criticize.
So taking the job is a gamble unless you're someone who's already wrapped up in the mess. For Summers, it might be worth it to ensure that the Harvard debacle is not the coda to his public career. But I suspect anyone else would think long and hard about how much they wanted to risk for the chance of glory.