The full impact of the final debt ceiling agreement/credit downgrade probably hasn't shown up in polls yet, but the initial indications are that this hasn't affected Obama's approval ratings at all.
http://www.pollingreport.com/obama_ad.htm
His ratings are essentially the same as they were in mid July - the middle of the debt ceiling crisis.
His approval ratings have gone down some from the beginning of May, however. Looking at those drops, Obama's strategy for 2012 should be to swing back to the left. There's been a slight decrease in the number of people that think Obama is too liberal, but not enough of a decrease to counter the number of people that think he has become too conservative.
He should spend more time bashing Bush, too. Bush bashing never goes out of style.
http://www.pollingreport.com/budget.htm
44% blame Bush for the federal deficit, while Obama and Congress each get the blame from 15% of the people.