Vida just published The Count 2010. It's an accounting of all the female book reviewers and reviews of books written by female authors published by the major outlets last year. Here's just a tiny piece of their findings:
Go read the whole thing. Only on one chart do the women outnumber the men—11 poetry books written by women were reviewed by Poetry Magazine last year, as opposed to nine poetry books written by men—and the male representation almost always vastly outnumbers the female. This is really sad.
(Thanks to books intern Anna Minard for bringing this to my attention and bumming me out.)