The biggest shocker at Comic Con was the premiere of a 3-minute trailer for Tron 2. The reason why it was such a shocker is that, as far as anyone knew, the film hadn’t even gone into production. But the trailer featured a fantastic completed lightcycle chase. So how did it come to be?

Jim Hill explains all the behind the scenes happenings of this project in detail on his blog, but here is the basic details: John Lasseter got behind the project. Disappointed with the direction Steve Lisberger was going in, Lasseter hired Lost writers Eddie Kitsis & Adam Horowitz to overhaul the screenplay. And as we reported a while back, the mouse house hired commercial director Joseph Kosinski (you can see some of his fantastic work here) to helm the project.

But the guys at Disney weren’t yet convinced that Kosinski’s vision of Tron 2 would be commercially viable. So Kosinski spent six months with Digital Domain creating the three-minute-long sequence which was shown at Comic Con as a teaser trailer. And judging by the fan reaction at the Con, I’m guessing that Disney will fast track the sequel into production to meet the announced 2011 release date.