I want to agree with and reiterate Ken's excellent first paragraph above. CD offered quantum improvements for the mainstream music listener, the likes of which we will not see again. Sonics aside, the covenience, ease of use, and longer playing time made it a slam dunk to succeed, plus it sounded better to most people in their systems, much better. By comparison (not in absolute terms),SACD and DVD-A offer neglible improvements,except perhaps for multi-channel.
I bought an SACD player and I'm rooting for it all the way, but I think the real problem is not Sony but the fact that most people will not find the benefits of it sufficiently compelling to make the change. On the other hand,if we see a flood of hybrid disks at CD prices, we might have something. Will that ever happen?