This was heavily inspired by this morning's discussion of Typeset.js (https://news.ycombinator.com/item?id=10076672), a similar pre-processor written in Javascript. Several commenters complained about not having a similar utility in Ruby.
Now it should be easy to make it into a Jekyll plugin! =)
So, I'm not the only one who was thinking that. Nice! :-)
If you do make it into a Jekyll plugin, please let me know! I'd love to see (and use) that.