HBO has set the dates for two of its acclaimed returning series this fall, both of which will be starting in with their third seasons - Boardwalk Empire (starring Steve Buscemi), which will air Sunday, September 16, and Treme, which will start Sunday, September 23.  Treme, which will return for 10 episodes, usually premieres in the spring, but HBO chose to start Game of Thrones earlier than last year, and pair it with two new half-hour series, Girls and Veep rather than the New Orleans-based drama.  Still, the wait for fall may benefit the series, which will now be running after perhaps a more appropriate intro in Boardwalk Empire.Treme will also be adding two new characters in its third season - Sam Robards (The West Wing) will portray a restaurant investor (hopefully for Janette!), and Chris Coy (True Blood) will be on board as a character based on reporter A.C. Thompson.  Hit the jump for more on Treme's upcoming season, along with some scoop on the season premiere of Boardwalk (spoiler alert for the latter, though with ample warnings).Treme creator David Simon as well as series contributor George Pelecanos have both mentioned they would like to see the series wrap up in its fourth season.  Despite the series' modest ratings (it's one of HBO's lowest-viewed programs, averaging 605,000 viewers for Season 2), HBO has said "When he tells us he's finished with his artistic expression of this, that's when we're done." Simon has also said that the third season will focus more on crime (which viewers of some of Simon's other series, such as The Wire, will know is a subject he handles deftly).The HBO series focuses on drama faced by New Orleans residents in the aftermath of Hurricane Katrina and stars (as part of an ensemble cast) Wendell Pierce, Khandi Alexander, Clarke Peters, Melissa Leo and David Morse.  As mentioned above, it returns Sunday, September 23 at 10pm.(BOARDWALK SPOILERS START HERE)As for Boardwalk Empire, a recent teaser trailer for the upcoming season shows more strife between Nucky and Margaret, especially in the explosive wake of Jimmy's tragic demise.  Speaking on an Academy of Television Arts and Sciences panel show creator Terrance Winter revealed that the new season will open a year after the gripping finale:

"It's New Year's Eve 1922, going into 1923.  The world has changed quite a bit.  Things have gotten quite a bit more violent as Prohibition has gone on and people are running out of liquor.  Hence Nucky's world is going to change."

I'm hoping Richard Harrow has had time to load up his arsenal of sawed-offs.

The third season of this 1920s Atlantic City gangster drama returns with 12 new episodes Sunday, September 16 at 9pm. Watch a teaser trailer below.