From 2005 to 2010, the percent of U.S. adults identifying themselves as smokers fell from 20.9% to 19.3% -- about 3 million fewer smokers than would be expected. The results come from the CDC's national telephone health surveys.
More remarkably, adults reported smoking far fewer cigarettes: The proportion of adults reporting smoking more than a pack-and-a-half (30 cigarettes) fell from 12.7% in 2005 to 8.3% in 2010.
A recent JAMA article lends historical context: In 1965, 22% of Americans smoked more than a pack a day (20 cigarettes); in 2007, 7.2% did.
Of course, this didn't count new customers (i.e., kids), in whom rates have been steady. Public health authorities blame smoking in movies and ads in teen-targeted magazines for recruiting lots of young new smokers each year. What we need IMHO is a summer blockbuster called "Ernest Gets a Tracheostomy." New cigarette warning labels coming soon, e.g.:
Vital Signs: Current Cigarette Smoking Among Adults Aged ≥18 Years --- United States, 2005--2010. Morbidity and Mortality Weekly Report (MMWR) September 6, 2011 / 60(Early Release);1-6.