I seriously doubt that you'll see an "official" push to add an OpenCL API to the core of perl(either 5 or 6). It's just not something the majority of perl applications would need to make use of.
What you might see eventually is perl bindings for OpenCl in the vein of PyOpenCL. But for that to happen you'll need an individual, or a group of individuals to be inspired to actually write those bindings.
It might be worth asking this on the PDL mailing lists. PDL is a project that involves the efficient manipulation of multidimensional arrays in perl. So people working with that might be inspired to experiment with GPU programming.