Rob, I understand your point completely. I think you may not have read mine entirely right. While I think our discussion about the relative merits of different formats is interesting, my main point was and still is that it will have zero impact on what the companies in their infinite wisdom will bring out. Only they know the reason for their ultimate decision.
As to Blu-Ray, there's still great uncertainty as to which format, Sony's or Toshiba's, will be out first for HD DVD and whether both (like SACD & DVD-A) or only one (like VHS) will survive.
As to everything besides movies migrating to hard drives, I see less clearly than you do. While MP3 is extremely popular for portable music, the younger crowd, and perhaps the general public, most audiophiles seem to still much prefer the better sound of LP(!) and SACD.
I do not know what format for higher-quality sound will replace SACD and DVD-A, but I wouldn't bet that it will be hard-drive based. It could very well be HD DVD. It seems to me that reason and logic, at least as we see it, may have little to do with the companies' ultimate decision.