If Blago really had something on Obama don't you think he would have used it to better his case? Also, on one of the tapes they keep playing, Blago really disses Obama. Remember, Obama wanted the criminal Valerie Jarrett to get the senate seat and Blago wouldn't do it. Time will tell, but I'd be surprised if Obama cuts him any slack.
As egomaniacal as BO is, He is still a peon serving the larger master of the Democrat party. He will do as he is told, just as Blago did. There may be in fighting amongst the party elite, but it doesn't effect their stategies. Blago knows he will get the pardon, that's why he kept his trap shut and fell on the sword. He didn't need to cut a deal with Fitzgerald.