Earlier quoted context omitted.
I (Evan Phoenix, author of the the article and project lead) talk with the Unladen Swallow guys almost daily. We've met up in person a number of times and have traded a lot of ideas, so I'm 5 steps ahead of you!
Unrelated question: is there a reason the docs in the git repo aren't rendered at http://rubini.us/documentation ? They seem well written and it'd be nice to be able to browse it from the website.
The short version: with one thing and the other. I was working toward that at one point but it fell by the wayside. Good reminder, though, should get those up there. In the interim, of course, rdoc + doxygen should work for you locally.