I think the Obama team walked Romney.
This is a media narrative setup from the beginning. Obama is weakest on the economy, and they knew that it would be nearly impossible for Obama to do well in this debate. It's no accident that Obama didn't mention the 47% comment, Bain, or tax returns. They're saving those for the town hall.
Obama is going to draw an imaginary line with him arm down the middle of the audience, and say that that half of the room represents the people who Romney considers victims and doesn't care about. Then he'll bring up Bain and Cayman tax shelters, and go right at the live audience with every attack he's got.
They're smart, but not that smart.