The generally accepted date is April 2007. Remember that before JL can join OW, all 6 of the other OW airlines (excluding EI) must have completed the changes to their computer and manual systems to accomodate JL; as well as JL having converted to OW standards (little things like accepting e-tickets). So there are a lot of disparate projects that must all be completed before JL can join. I guess MA and RJ must also be ready for JL before JL can join, but maybe JL will join before they do (I doubt that).