In my ideal world you'd be able to mark a function "this should compile to / run on gpgpu" and the compiler would potentially tell you why it can't do that. I'm not even sure if anything is stopping us apart from implementing that apart from the effort required. Sure, many ways to write that code will result in terrible performance, but it would still be closer to the auto-vectorisation experience.

Actually we already have openmp to cuda (http://www2.engr.arizona.edu/~ece569a/Readings/GPU_Papers/3....) so just making it more production-ready would be perfect.