In the document "Using Intel C++ with Intel Processor Graphics.pdf" it talks about Processor Graphics Offload.
Is Cilk Intels response to HSA? Will it be possible to have cilk generate HSAIL so it supports AMD APU graphics offload?
(note I posted this question to the intel opnecl forum as well OpenCL vs Intel Cilk Plus Issues, Differences and Capabilities)
I would say that Cilk is more comparable to C++ AMP (or, to a lesser extent OpenCL) -- a "parallel programming language" (not a great term but I can't think of a better one at the moment) which can potentially be implemented on a number of different hardware platforms (although I don't know if there are plans to port Cilk to other platforms).
HSA is more of a platform specification designed to optimally support parallel programming languages across multiple hardware and OS platforms.