I have watched the basic server offerings for this very animal.....and it looks dismal. Olive, Escient, and AudioRequest..........no plans for multi channel servers....
Stereophile did a review of the Linn Klimax.......which was kind of a hirez server.....read the article
here to get an idea of what this entailed. It was very complicated and verrrrry pricey. I picked Olive as the choice for hi rez plug and play because they seem to cater to classical audiophiles......which would be the one target audience for sacd multichannel listening. There may also be some complicated copyright stuff involved, too.
I wouldn't hold your breath on this one. The best bet would be to bone up on your computer skills and see what is happening with 5.1 sound cards. That seems to be the wave to watch.....
Although I haven't checked the movie dvd servers to see if they capture the whole movie in surround sound..........