Combining Promises+ES6 Generators seems the next way to go. It is already used successfully in many Firefox tests and the syntax just feels great. For the Node.js ecosystem, you should take a look at IO.js [1], Koa [2] and co [3] that are able to handle nice async syntaxes.
[1]: https://iojs.org/ [2]: http://koajs.com/ [3]: https://github.com/tj/co