In order to simplify 'SBCL Compiler Internals' book reviews (and to avoid bothering sbcl-devel mailing list with the book-related things), I have launched my personal blog: http://insidelisp.blogspot.com/
Currently there is Chapter 1.1. I will add more chapters when they are done.
I also maintain PDF version of the book, but I will probably not send it to sbcl-devel once per month, as I have suggested before - it will be better to include the final book into SBCL distribution someday, instead of sending PDF drafts here.
In case you wish to read PDF anyway, mail me and I will send it to you. But notice that the blog and PDF versions are equal.