I listened to the demo using some 'proper stereo headphones' (I don't want any of this USB rubbish that completely bypasses my ASUS Xonar

) and I was quite amazed by the demo actually. Had to turn my volume up a fair bit, but this definitely made for a more atmospheric and believable experience. I'd love to see (or hear) this sort of thing in games.
On a side note I'm finding it very tricky not to switch to AMD. With Mantle, True Audio and their superior mining capabilities. I'm actually only really holding onto the green card at the moment because, as a monitor reviewer, I want to be able to test Nvidia G-SYNC.