“Things are changing in Atlantic City,” vows Jimmy Darmody in this new teaser for the second season of Boardwalk Empire. Maybe so, but there’s still plenty of gun-fighting, old-timey Klan and images of creepy corridors that make everything feel vaguely claustrophobic. Also, threats from Nucky. Never change, Boardwalk Empire! Never change. Buscemi and Co. will be back in September, and an HBO spokesperson says an exact premiere date will be announced in the next month or so.