OpenCL is basically a way to make GPU shader cores programable. Nothing more and nothing less. This allows the CAPABILITY to offload massivly parrarlel operations to the GPU (Physics, for instance), but only if someone writes the routine using the OpenCL language.
And of course theres the significant downside that by using OpenCL, you eat GPU resources. And lets face it, unless you have something that REALLY bottlenecks the CPU that is also parralel in nature, it really doesn't make sense to steal power that can be used for Rendering instead.