Grey’s Anatomy will bid farewell to 2009 later this season when the Seattle Grace staff celebrates Thanksgiving, Christmas and New Year’s - all in one very special installment.

“We’re pretty excited,” show creator Shonda Rhimes tells TV Guide of the big Grey's Anatomy event. “We’ll be watching time pass as we take the audience into the new year.”

Sadly, this isn't to say all the news is warm, fuzzy and joyous.

From the sound of it, the Season Six drama shifts away from medical and professional drama and focuses instead on characters’ personal hopes, dreams and disappointments.

Over the holidays, “people feel like something magical or momentous should happen,” Rhimes explains, but certainly speaks the truth when she says “But often nothing does.”

Among other story lines, we'll be seeing how Bailey became Bailey.

In the episode, we will meet Miranda Bailey’s (Chandra Wilson) mother, whom Rhimes describes as “more Bailey than Bailey. You’ll finally see where Bailey gets her stuff.”

In between unwrapping gifts, Mark and Lexie’s happiness will be rocked by the arrival of a character from his past who Rhimes says will cause them “to fall on hard times.”

Meanwhile, over on Grey’s Anatomy's sister show, Private Practice, Addison Montgomery (Kate Walsh) will be getting a surprise visit from her dad, whom she calls “The Captain.”

He's played by Stephen Collins, while her mom, Bizzy, will be played by JoBeth Williams.

Over a three-episode arc, kicking off in mid-November, Rhimes says Addison will finally get to the bottom of some more of the redhead's “shocking family secrets.”

Well, it is the holidays, right?

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.