In that "World War Z" trailer at :44, right after the British female voice over says, "It was happening in small villages" there is a glimpse of the movie "28 Weeks Later", the sequel to "28 Days Later". So apparently "World War Z" is the third installment of this so-far excellent (IMO) franchise. Interesting to see Brad Pitt in a zombie flick. I wonder if it's a leading role or a cameo.