Star Wars will never appear on Blu-Ray until GL has finished tinkering with the saga enough to allow them onto it. He's working on the IMAX'd versions of Star Wars, probably still has loads of 'ideas' to go back and destroy the original trilogy even more.
Steve Sansweet did make a comment at the Europe Celebration that Blu-Ray wasn't on the radar of Lucas yet and wouldn't be until it was firmly established as the media of choice. Until DVD dies, it won't happen anytime soon.