Something I've heard about is integrating Guile into Emacs. Will Guile become the primary language for Emacs with Emacs Lisp as an option, or will Emacs Lisp remain the "default" choice, with Guile for those who want it? And does anyone know what sort of timeline we're looking at before Guile support is released?
Seems to be going quite slowly. However, I would think getting a good Scheme implementation as the Emacs default is probably the single most important feature. All Emacs is, after all, is a Lisp interpreter.
Emacs users and developers would continue to write Elisp. The difference is that Elisp would be running on the Guile VM, which will improve performance and bring some features that are currently missing from Emacs (threads, and some other stuff that I can't remember).
Take this with a grain of salt, but I believe that Emacs Lisp will be implemented on top of Guile. More precisely, ELisp code will be compiled to Guile bytecode (which runs on a register VM[1]), which should make ELisp code run faster.
As a result, Guile and ELisp code will be able to play together.
