Lost, Alternative Reality?

I'm still not sure how seriously to take all the videos at the Lost Comic-Con panel, but having seen some of it so far, they're at least thought-provoking. Several of the vids suggest that we're going to see an alternative universe in which the bomb blast did change time and avert the crash of Oceanic 815. Or maybe the producers just want us to imagine what that would be like, and talk about it. So please do.