Seven Languages in Seven, er, Months

A week or so before Christmas, an intriguing book popped up on my recommended list at Amazon. This was Bruce Tate's Seven (Computer) Languages in Seven Weeks (ISBN 193435659X). The idea behind the book is to teach certain programming concepts through the medium of the languages that embody them the best. Object orientation and dynamic typing are taught using Ruby, a language in which Tate does most of his work; prototyping, which I'm not very familiar with, is demonstrated through Io, a language I'd never even heard of before; functional programming is through Haskell; concurrency (using actors not threads!?!) through Erlang, and so on. There is also a chapter on Scala, which I've had some experience of, so I'm intrigued to see what he has to say about that.