The video is not overly long, so it's not exactly jammed with new information. I did find it interesting enough, however, to hear Gyllenhaal talk about the two different drafts he got to read of the film -- before and after Fincher came to it. Further questions include, how Gyllenhaal "discovered" Fincher and which of Fincher's works he likes the most, which qualities he ascribes to Fincher as a director and whether he believes the Zodiac Killer is still alive today.
Here's the link. Enjoy:
[video] Jake Gyllenhaal Interview