I think the domains of use will be quite different. Since Rust doesn't require a GC or other runtime support, we envision it being used in specific modules to provide a boost to code otherwise written in JS. See https://hacks.mozilla.org/2018/01/oxidizing-source-maps-with... for example.

By contrast, for a language like Go, it's probably more practical to ship entire apps, rather than embedding in libraries, because there's significantly more overhead in terms of runtime system support.