So ruby-debug is still broken for 2.0, but someone came up with a package called byebug. Check it out.
To install it, just use npm:
$ npm install -g node-inspector
Since you’ll be connecting to node-inspector via your browser, you’ll need to spool up the node-inspector server as so:
$ node-inspector &
Finally, run your app in –debug mode:
$ node --debug app.js
Connect to http://127.0.0.1:8080/debug?port=5858 and you’re good to go!
This setup description and more info can be found in the README.