I think that Shinichi will come up with some master plan to save everyone and defeat the BO, but in the end he will be forced to choose between saving someone he loves or returning to his body, he than will of course save the person and if all goes as I want he will grow up and be with Ai. Yes I know this is unlikely, but I wish it would happen. I like the RanxShinichi pairing as well, but I want Ai to have a happy ending and Ran could marry another and move on as well because face it if Shinichi ever tells Ran he was Conan when he changes back won't there relationship be a little messed up.