[petercooper]

I don't see that much demand for it. For example if you look on the HN seeking freelancer thread, most people are still looking for RoR or PHP.

True, but HN is not particularly representative of computer science or software engineering related fields (well, it is, but only a small percentage). There's a lot of stuff going on out there both in industry and academia that doesn't make it here or get particularly represented in the jobs/freelancer threads.