Currently they are confusing. *My* personal understanding is that, currently:
You need a Quadro card,
You need to use Stereo option 10,
You need to have the emitter connected at boot, and keep it connected,
You need to connect the VESA sync output on the Quadro to the emitter,
You need to have one of the monitors supported in the driver, being this list for the release version: http://www.nvidia.com/object/quadro_...rds_linux.html
Note that none of the 3D Vision capable 1080p monitors are currently on the list. Perhaps more are supported in the Beta.
Good news that we might be able to use USB only in the future.