Seems like you would still need to provide something like syntax objects and a special API to manipulate them?

This involves a longer discussion, and I'm not sure what Tim is thinking along those lines. Suffice to say, Clojure's macros are always going to be the best, but I have pretty high hopes that you can get 95% of the way with sweet.js. :)

Yes indeed. Sweet.js already uses syntax objects internally so the groundwork is there for syntax-case. We "just" need to implement and surface the API :)