I don't think it's the most recent, isn't 'i am a strange loop' a subsequent one? Anyway, I read it and it's awesome. It is a much more personal book than GEB though, and it's easy to grow weary of the poem tranations after the twentyeth, but it's a great reading.
I meant most recent "mega-book" since its a brick like GEB (but not sure of the size of "I am a strange loop", so maybe that's a brick too)
I can see how the poem translations can get weary, but they do a brilliant job of illustrating his ideas about translation way beyond poetry. I love how he generalizes the idea of translation into all sorts of non-language domains (i.e. translating ice skating skills to roller blading). Now to get past the current set of poems onto the next chapter ;)