This reminds me of one of the points pg makes in What Made Lisp Different [1], under #9:

  "compiling at runtime is the basis of Lisp's use as an extension language in programs like Emacs"

This Excel capability is an extremely cool demonstration of where ClojureScript's self-hosting capability can take us. Seems like there's no stopping it. Kudos to Christian Felde!

[1] http://www.paulgraham.com/diff.html