So he stays, apparently at Obama's behest, as I suspected would happen.  The only way this works out is if Obama is planning on using his "mercy" to Lieberman as a marker when it comes time to get things done.  Because when that time comes there are going to be shrieks of "Partisanship!  Partisanship!"  coming from a lot of different sources, and Lieberman could easily be one of them.  And leaving him in control of an oversight committee -- that's like leaving Aldrich Ames in charge of counter-espionage after you've discovered he's a spy.  Lieberman is perverse and narcissistic enough to use his spot to eff with an Obama Administration given half a chance.  If he's removed after starting some bogus, Whitewater investigation, he can bask in a martyr's attention and claim the Democrats are just covering their ass.  This isn't necessarily likely, but why give someone as demonstratedly perverse as Lieberman the opportunity to do what he does -- behave perversely?  Get rid of him now, while it's cheap, easy, and painless.   He's a risk the Democrats don't need to take.    
On top of it all, taking his useless, duplicitous ass back means it'll be that much harder to beat him in 2012.  I simply can't get over the optics of it: Lieberman behaves as a traitor to "his" party, Reid calls him in and says he's going to punish him. Lieberman, from a place of no leverage, says "That's unacceptable," and the Democrats back down.  What in the fuck goes on in Washington?