One of the features that's supported by NVIDIA's binary Linux driver that is not supported -- nor has even been attempted -- by the community Nouveau project or any other open-source project is for 3D Vision / 3D Vision Pro. 3D Vision is NVIDIA's technology that combines their consumer and workstation GPUs with specialized glasses and capable displays/projectors to provide a realistic 3D experience. 3D Vision Pro is effectively the same but with a focus upon the professional/enterprise markets by creating an immerse experience in Autodesk, Maya, and other costly applications.
This is obviously a very small market for NVIDIA right now with most users not having the appropriate 3D glasses, which can easily cost over $100 per pair, or the displays that are also significantly more expensive than normal LCD panels. The software/application also needs to support this 3D technology.
NVIDIA has supported 3D Vision for a number of months now in their proprietary Linux driver, meanwhile they don't support Optimus Technology on Linux
or other features that are actually used by a greater number of customers.
Yesterday, NVIDIA even put out a new binary Linux driver release where it's sole official change is a 3D Vision bug-fix.
Updated the NVIDIA X driver to not update mode timings for G-Sync compatibility when NVIDIA 3D Vision or NVIDIA 3D VisionPro is enabled along with a G-Sync device.
This is the only official change in their new 260.19.44 driver release, while all work right now has been focused upon their soon-to-be-released 270.xx series.
So why is NVIDIA focusing so much on 3D Vision / 3D Vision Pro under Linux? It's very likely because of an enterprise customer or a distribution/purchasing deal that is about to take place. Similar to how multi-card SLI (Scalable Link Interface) came around for Linux back in 2006 likely because HP wanted it
for some of their workstation systems at the time. But who exactly is behind this 3D Vision Linux focus is a mystery for now.