I just received the final version of DSLs in Action, a book I reviewed for Manning.
The author included in this version an example regarding Xtext, probably I was not the only one to suggest it.
Now I am writing a short review to post on Amazon.
In my opinion the part on internal DSLs is great: it is very pragmatical and there example using a lot of languages. I have to suggest taking a look at this book.
And they even pick a sentence of mine to put on the cover, wow, I am happy about that :D