I was just watching the show formerly known as Mike and the Mad Dogg.  They just had Jon Heyman on from Sports Illustrated, who's at the Winter meetings.  Pretty reputable source, and he said the A's have just traded for Holliday. 

No word on who the A's are giving up, yet.  It's got to be pitching, though, right?  Regardless, according to Heyman the A's have just traded for a right handed, power-hitting 300 bat.  Wow!