Officials expect CoS to leave post to explore mayoral run this week.

See what the Chicago press is saying here and here.

Rouse seen by some as interim CoS.

And/But: Politico runs the rule over the permanent candidates.

Developing...

HALPERIN’S TAKE: The focus will be on Rahm (and the fact that he can raise likely 5 times what anyone else takes in for the race), but keep your eye on the ball: at this critical time, does the White House (a/k/a: the President) handle the transition to its advantage — rather than the alternative.  It’s not just WHO Obama picks, but how the choice is unveiled.