I just came across a nice interview with Michael Stuhlbarg at collider.com. Stuhlbarg is playing Arnold Rothstein, the Jewish gangster who was possibly responsible for fixing the 1919 World Series. The interview talks a little about the upcoming shooting schedule. Stuhlbarg mentions that shooting on the series order of 11 episodes will start back up in October and end in December or January. He also mentions a possible fall 2010 series premiere, which agrees with a lot of the current speculation.
Your source for news and discussion of HBO's Boardwalk Empire television series, and the book it's based on, "Boardwalk Empire: The Birth, High Times, and Corruption of Atlantic City," written by Nelson Johnson.