Well, okay, maybe SACD's aren't all that successful, but they do still produce them. B-ray might be a more popular format providing BD does really take off. I certainly would like to see it happen - but they need to market them with a CD version (or hybrid SACD) like some DVD-A releases have in the past.
M.R. et al - happy dreaming. . .I think the only hope for audio-only Blu-ray is in classical and perhaps jazz recording. One thing to note, however, is that the new Blu-ray players do NOT play SACDs - leaving those of us who have a collection out in the cold - at least so far. The BD audio discs would fill the gap, but that's only if the Audio Faithful gravitate to the format. I'm on the sidelines - watching. . .
PS - only 30 CDs left to freeze and polish with lens cleaner. It's been a long, sloggy experiment, but one with quite excellent results! Warmer, smoother sound all 'round, and a happier Swampville resident. (grin)