Currently sitting on the lovely Easter Island as I type, I can only speak for the flight I got over here, but they seemed to be handing out Economy-Business class upgrades like candy at the gate (I got given one, and there was at least five other people called up as well). I´m just OW Sapphire, and on a LONE5 ticket, so certainly wouldn´t think I was at the top of the list for upgrades either. I´m sure you´re not looking towards the departure time lottery though, especially with a paid business class ticket. No doubt others out there have more experience in that area!