That sort of works, in the http://blog.sigfpe.com/2008/12/mother-of-all-monads.html sense. Promises are an awkward encoding of continuations, and so they can encode all monadic structures.

It sort of misses the point, though in a way which Javascript is incapable of expressing. Namely, that the principle of least power is a good thing, and you should restrict yourself to contexts which make only the operations you want accessible.