The New Yorker printed some pages from it a few months ago. It's wonderful. Robert Crumb is a lot of things, but first of all an artist, and he has brought a new perspective on the Bible, which has plenty of sex and violence in it. He spent four years on this and this is some of his best work.
http://www.smh.com.au/news/entertainment/books/explicit-genesis-upsets-christians/2009/10/18/1255800503029.html
I'll reserve judgment until I can see it. It could be a clever statement, a fun book, or just a ploy to get attention by getting Christians to throw a fit. Until I see it, I can't say which it is.