Not really. The talk that tweet is about was on the module loading system and was a demo of Dave Herman's experiment of adding a hook to the module system. The traceur compiler transforms js extended with various js.next proposals into (ugly) js that will execute in current browsers. You could define a traceur hook in Dave Herman's system to get the traceur extensions in Firefox today using Narcissus/Zaphod.

As for getting the Traceur features in coffeescript, all you'd have to do is add the new traceur keywords to the coffee grammar as keywords (to avoid treating them as implicit function calls) and then run the coffee compiled js through traceur.