I don't think it's a hardware issue. It's a matter of the software that can decode it. I read a while back that some company was working on DVD-A decoding for PC's. SACD's that contain a CD layer would work at least for that layer.
i'm guessin the sacd would be a raw read with software decode. dvd a.... should just be software. stupid dvd people shouldn't have separated the two from the start, they'd have an installed base of millions of dvd-a compatible players if they didn't get all high and mighty with their copy protection builsh*t. now dvd-a is dead in the water.