OpenCL 1.2 was unveiled in late 2011 (and has already been succeeded by OpenCL 2.0 in late 2013). OpenCL 1.2 added features like better image support, separate compilation and linking of objects, device partitioning, and many other changes. NVIDIA though has lagging behind AMD in supporting OpenCL 1.2 by their Linux graphics driver.
A sharp-eyed Phoronix reader pointed out that within last week's CUDA 6 release there is an OpenCL stub library (libOpenCL.so) and it has all of the new OpenCL 1.2 functions plus other new OpenCL functions.
This libOpenCL library though is just the stub implementation and depends upon the actual OpenCL support implemented within the Linux graphics driver, which is where the OpenCL 1.2 support has yet to appear. As of the new NVIDIA 337 series there still isn't any OpenCL 1.2 GPGPU support but let's hope it will come with the R340/343 series -- it's with the Release 343 series where NVIDIA's dropping their pre-Fermi hardware support and moving it off to a new legacy driver.