Emacs itself isn't sexy; the sole reason I use emacs is the power and extensibility offered by emacs lisp. If vim used elisp instead of shudders vimscript, I would use it in a heartbeat.
org-mode and w3m (a web browser that can be integrated in to emacs) are my two biggest draws, but eventually I mean to get the mail client working, give the shell modes another try, and maybe get the irc and RSS clients going too. The sky's the limit with emacs, while vim does more closely stick to being just an editor.
All that said, I still use vim when I need it, such as for getting syntax highlighting of strace files, which last time I checked, emacs did not have a mode for. vim is also often much faster on large files.
I really hate the key combos though.
So of course the solution is to suffer the bad shortcut placement in Emacs long enough to not need tutorials and fully understand what you're doing, then throw all the intuition you've gained out the window by remapping everything.
>NOTICE: The main purpose of the Emacs tutorial is to teach you the most important standard Emacs commands (key bindings). However, your Emacs has been customized by changing some of these basic editing commands, so it doesn't correspond to the tutorial. We have inserted colored notices where the altered commands have been introduced. [More]
[More] is a list of the default keybinding, the command, and how to access the command in "your" emacs.
The keybindings are also changed throughout the entire manual (C-h i) I believe.
Regarding extensibility, would it even be possible to embed Guile or ECL (or Lua or John Walker's ATLAST) into an existing editor? Perhaps not Vim, but maybe classic vi or nvi?
Last I checked, almost all vim scripts were written in vimscript (with Python starting to make some headway). If any non-vimscript language is going to be the future of vim scripting, it's probably going to be python rather than Lisp or Scheme. So if you were going to start writing Scheme scripts in vim, you'd be pretty much the only one.
Compare that to emacs, where virtually the entire gigantic emacs ecosystem is written in Elisp. It's an Elisp ecosystem and community you'd be participating in were you to write in Elisp for emacs. Leveraging that enormous codebase and community is a huge win for emacs that you're not going to get in vim unless you program in vimscript or maybe to some extent in python.
So if you're interested in vimscript or maybe python, vim seems like a good choice, while those interested in Elisp or maybe Scheme would probably be much better off in emacs.
As for Lua, how many vim scripts are written in Lua? I would guess it's about as popular as Scheme is for vim, which is to say virtually not at all. In any case, it's not a Lisp, so I'm not sure how much interest there would be from the Lisp/Scheme communities in programming in it vs something like python, which seems to have more traction in the vim world. It would be a step up from vimscript, though, that's for sure. But, again, there is no Lua ecosystem for vim, so being the only one writing Lua scripts for vim is not hugely attractive for most people.
Just my two cents.