Yes, it's possible, but I'm not holding my breath. Akin could get back into the 40's, but can he top, say, 46%? That may be his ceiling, and only if he makes a good recovery. But I'm not sure he's capable of that. Conservative Republicans like me will vote for Akin over McCaskill, and there are others who also are ABOC (Anyone But ObamaClaire), but I doubt they would be enough to gain the victory.
Also there’s going to be a highly motivated turnout to vote AGAINST Akin.
And of course, those people will think “Hey, as long as I’m here, I’ll vote for Obama, too.”