Am I wrong or isn't this just kind of DVD-A's version of a hybrid SACD? But you have to flip the disc? DVD on one side, CD on the other?

I still don't understand why SACD isn't taking off. A hybrid disc (which most of the newer releases are) will play on ANY CD or DVD player. If you're lucky enough to own a uni-player or cd/sacd player then you also get the added bonus of a 5.1 mix.