If they had faked it and were using SoftTH, is SoftTH compatible with 3D Surround? Obviously they were in 3D mode in that demo.
The first link shows how to setup softTH with 3D vision on 3 screens, which was an answer to sbucklers question of how it could be possible to show this if the drivers weren't ready.
Nvidia might have things ready, but its not impossible that the setup can be a mockup as well. JHH showed with Fermi and wooden screws that they are not above showing mockups of products to come.
My point is that its pointless to "show they have it", since they also were supposed to launch it already, have advertised it and sold it as surround capable and not delivering.