The last I heard about the Argonauts book was in a post from Adam Jury from February of last year (so, about a year and a half ago) stating it was in the writing/editing process.
I've been away from everything Eclipse-Phase-related for over a year now, and having just returned to the forum, I can find no trace of the book. Did it ever get released (possibly under a different name, or incorporated in some other book)? Did it get cancelled altogether? Is it still in the works?