Obviously: Since Zodiac already came out and was well covered on this blog during it's marketing prime-time, there isn't any real news in this; at least not relating to Fincher. But if you care to hear some of what one of Hollywood's most successful writers has to say, this is definitely for you.
The Collider folks were nice enough to include a time-index for each topic. So you can get to whatever topic you are interested in quickly. The Fincher part starts at 6:00 into the interview.