To anyone who hasn't, I recommend downloading the sample PDF - the available first chapter is a decent size and a great read. I am looking forward to seeing the rest of it!

Here's an excerpt:

  I’ll start by teaching you just enough Clojure to be   
  dangerous. Then we’ll use that knowledge to embed an  
  object-oriented language within Clojure in a more-or-less  
  conventional way.

Now if that doesn't sound like an exciting start I don't know what does.