Unlike f2f I do believe this should be possible without a lot of problems. NaCl isn't that special magical technology and everything that is special needs to be

Unlike f2f I do believe this should be possible without a lot of problems. NaCl isn't that special magical technology and everything that is special needs to be in an RC anyway. And even if you have any implementation bugs; the way NaCl works, this would, in the worst case, mean that the program gets killed because it contains invalid machine code or makes invalid syscalls (this confidence comes mainly from the fact that go uses the unmodified NaCl runtime for execution, which contains the appropriate check and is QA'd by the chrome team). I assume that, so far, just no one did the work, they don't want to spend the additional resources on separate playgrounds or the go team doesn't consider it a good enough idea. I'd recommend either E-Mailing golang-nuts or directly opening an issue (after checking, that there is none so far).