Holy shit, Chabon has updated his site!
Apparently, his new novel, The Yiddish Policemen's Union, "will be published in January, 2007. Really. No, really."
Let's hope that the story is better than than the title.
Believe it or not, I preferred Chabon's original title, Hatzeplatz (or Hotzeplotz, according to this 3-year old article that provides some background).