Yannetti did the opening, so I'm pretty sure that Jackson will do the closing. And I bet they have charts and visuals they've been working on to lay out their whole view of the case. I fully expect he'll hit it out of the park.
I'm actually very curious about what Lally will say during closing. How will he excuse Proctor's actions? Will he stick with his reconstructionist's theory with the whole "John's arm hit the back of the SUV and launched him 30' backwards" thing? How will he explain away the discrepancies in the timeline that his own witnesses have introduced? I doubt he has it in him to rise to the occasion. I expect he'll just mumble his way through a completely unmemorable closing the same way he did the opening.