Overall the book is interesting, but there are some issues that detract from what would otherwise be a great companion to the series.
First of all, there are a number of glaring editorial mistakes, i.e. spelling errors, incorrect words, duplicate sentences, and so on. In one paragraph alone I counted four mistakes: honestly, how does that get into the final printing of a book?
Secondly, I felt like I was reading "Battlestar Galactica and Psychology" more so than philosophy. That's not necessarily a bad thing, but I was expecting something a little different. Many of the articles dealt with the theme of identity issues, which is definitely relevant but it is somewhat redundant after the third or fourth essay on basically the same topic.
Thirdly, the essays are a mixed bag: some are excellent, others are not so much.
Finally, clearly the essays were written/the book was published before the series was over. While this is not a major problem, many of the speculations of the various authors turn out to be wrong, and this takes away from the book in my opinion.
Again, overall it's not a bad read. Some of the essays are quite insightful and thought-provoking and add a new dimension to the series, even if the focus is often psychology and not philosophy.