One of the changes that immediately generated interest in the new NVIDIA 334.16 Beta is 64-bit EGL and OpenGL ES support. A few months back with the NVIDIA 331 driver series there was NVIDIA Linux 32-bit EGL and GLES support but now it's finally been extended to support the 64-bit binary driver. EGL support is critical in eventually having the NVIDIA driver support Wayland and Mir. The OpenGL ES support is also important given the Kepler-based GPU found in the Tegra K1.
Other changes in the NVIDIA 334.16 Beta linux graphics driver are various RandR changes, improved support for the __GL_SYNC_DISPLAY_DEVICE / VDPAU_NVIDIA_SYNC_DISPLAY_DEVICE environment variables, improved performance for the NVIDIA X driver when handling large numbers of surface allocations, and experimental support for ARGB GLX visuals when Xinerama and Composite are enabled at the same time on X.Org Server 1.15.
This driver update also has many bug-fixes and other minor enhancements.
More details on the NVIDIA 334.16 Beta Linux graphics driver can be found at NVIDIA.com.