Yes, the older guy and woman with the backpack are almost certainly Bill Ayers & Bernardine Dohrn. Ayers was going to school across the street from Columbia (and Obama) in 1983.
Do you think there is the slightest chance that Barack Obama did not recognize the photo of those two staring back at him from the pages of his own essay? At first I didn't see the resemblance, but after looking at an old picture of them over at "zombietime" I realized that it does indeed resemble them. This picture.