Here's the Wiki page as well an article about the film.
The Guardian sheds some more light on the film.
They currently have three projects lined up to follow the triumphant No Country For Old Men. Burn After Reading - a caper about the CIA, gym culture and internet dating, starring Brad Pitt and George Clooney - is already in the can. Once that is polished off, shooting is set to start on A Serious Man near the Coens' hometown of St Louis Park, Minnesota. The Gopher State was, of course, the locale for Fargo, but in place of that film's memorably Scandinavian milieu, A Serious Man will be seriously Jewish. Set in 1967 and located within the town's Jewish community, it focuses on a college professor seeking advice from several rabbis while in the throes of domestic and
professional crises. Although the plot isn't autobiographical, the Coens will draw on their own experiences in this environment, including attending Hebrew school and being the adolescent children of academics. The picture also reportedly includes a sequence set in Poland a century ago, involving a rabbi and Jewish wedding customs and superstitions, which will be spoken entirely in Yiddish.