It's definitely in danger and from BluRay if not from eventual high-resolution downloads. If that is, you ever consider it to have taken off at all. I guess it has for classical music.
If you have a good enough system, then your CDs will sing anyway. I think it depends on your kit and on what you listen to and how.
Personally, I adore multichannel music, so the few SACDs I have I just love. The difference from CDs was huge for me, but most of that was down to the soundstaging and production of the material rather than hearing the extra resolution.
I have an SACD of Train - Drops of Jupiter and it's only 2ch. I have to say I can't see the advantage over the CD. They were both good, but I had been hoping for multichannel on the SACD. Will check more carefully next time!
My favourite disc of the moment is Keane on BluRay, live in London's O2 arena. What a fanastic disc. DTS Master Audio I think and just amazing. Thank goodness for multichannel music videos. That's what I love.