To be honest, I don't know which I'm more sick of hearing about, Podcasts or Bird Flu. But I guess the editors of the New Oxford American Dictionary didn't want to be alarmist this year and decided to go with "Podcast" as the Word of the Year. Along with Bird Flu, the other runner up was IED (improvised explosive device). Fun.
Podcast is 2005 Word of the Year [Macworld]