"Downton Abbey" trailer has fans wanting more

It's not going to be on the air in the U.S. until next year, but the trailer for season 4 of "Downton Abbey" is already getting the faithful viewers wanting more.

There are some new faces like Paul Giamatti.  He's joining the cast as Cora's brother, Harold, while old favorites like Maggie Smith as the Dowager Countess is returning.

"Downton Abbey" returns to PBS stations this winter, on Jan. 5.