For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
I don't know a great deal about it since I haven't read it myself, but from the reviews I have seen of it, it seems to be an OK read with some good history, but that the author has a problematic habit of ignoring how terms are defined in scripture to make prophecy fit his view, vs. letting the scripture inform his theory. As such, his conclusion is somewhat weak.
For example, redefining 'mother' to merely mean 'major' or 'best' - such as in English idiomatic use, while ignoring that all figurative uses in scripture use 'mother' as parent, originator, source, etc.