I apologize for the vagueness; I was away from browser when I sent that. Go to http://www.ecmascript.org for the nitty gritty on ECMAScript 4th Edition, a.k.a. "JavaScript 2", which is what I was talking about. White papers, specs, reference interpreter.
The link from the Firefox developers page (http://developer.mozilla.org/en/docs/Main_Page, which you get to by clicking the "Developer" tab on http://www.firefox.com) is called "The Truth about Javascript", and leads to slides from Brendan Eich's talk at last year's Ajax Experience West conference (http://developer.mozilla.org/presentations/eich-ajax-experience-2007/). Embedded within the slides is discussion about what went into the design of "Javascript 2", and a link over to the http://www.ecmascript.org site (as well as other interesting stuff).
