Early yesterday evening the White House announced it was nominating Neal Wolin to be Geithner's deputy at Treasury. This is interesting for a couple reasons--the first being that, as the announcement noted, Wolin already had an administration job: He was deputy White House counsel with jurisdiction over economic matters. I guess once you've been through two candidates for a position as high-profile as deputy Treasury secretary you're willing to juggle the organizational chart a bit.
Also interesting is the fact that Wolin is a close friend of Larry Summers. He was general counsel at Treasury when Summers was secretary in the late '90s/early '00s (and deputy counsel before that), and the two are said to be big fans of one another. From what I've heard, Wolin is very good at dotting i's and crossing t's, but also has real range as a policy wonk.
That's not to say Wolin isn't a Geithner guy, too. My understanding is that he was part of the Summers inner-circle at Treasury that included Geithner and a handful of other top officials.