That's the new Haruki Murakami book, due out in the U.S. in late October. It's over one thousand pages and it was published originally in three parts. My view of Murakami is that his later works are good but not special, and that his masterpieces are the early novels and also his non-fiction chronicle of the Tokyo gas attacks, Underground. My favorite is Hard Boiled Wonderland the End of the World, which also should appeal to science fiction fans.
IQ84 has been a smash hit in Japan and the never-easy-to-please Germans very much like it too. Here are other foreign reviews. I have read the first 130 pages and believe it may well be his masterpiece. It starts off with two dual stories, with what are recognizably Murakami-esque characters, but I won't say more than that.