Neil Mix implements similar transformations in Javascript in Narrative JS: http://www.neilmix.com/narrativejs/doc/. However, as I recall it aims more to provide some of the main benefits of continuations rather than a complete implementation of continuations on top of Javascript, which is more where I was trying to go with jwacs.
Jwacs introduces very little new syntax to Javascript; I'm curious to hear which bits you find jarring, and what you would have preferred to see.