Next Tuesday, Brendan Eich, the creator of JavaScript and Mozilla's CTO will be joined by several very special guests for a developer chat on the future of Mozilla's JavaScript technologies.
Brendan gave some hints at his recent Mozilla 2 Roadmap post:
For Mozilla 2, we will have a JIT-oriented JavaScript VM (details soon) that supports the forthcoming ECMAScript Edition 4 ("JS2") language. Among the desirable characteristics of this VM will be a conservative, incremental garbage collector (GC). If it makes sense, we can use this GC module to manage DOM object memory instead of using XPCOM reference counting. We can use its conservative scanning code to assist in cycle collection. And we can insert JIT calls directly into DOM glue code entry points (provided no JS mutation has overridden a method property value), bypassing the powerful but relatively slow typelib-based dispatching machinery of XPConnect.
If you're excited by those bits of information, then you'll definitely want to join us for this developer chat. The time is Tuesday at 10am (UTC-8) and the place is IRC server irc.mozilla.org in the channel #javascript.