Here are the specs for the ZODIAC Director's Cut due January 8, 2008:

The 2-disc set will feature a version of the film that's 162 minutes long (for the record, that's 4 minutes longer than the theatrical version). Extras will include audio commentary by director David Fincher, a second commentary by Jake Gyllenhall, Robert Downey Jr., producer Brad Fischer, James Vanderbilt and James Ellroy, 3 The Film featurettes (Zødiac Deciphered, The Visual Effects of Zødiac and Digital Workflow), 3 Sequence Breakdowns (Blue Rock Springs, Lake Berryessa and San Francisco), 5 The Facts featurettes (This is the Zødiac Speaking, Lake Herman Road, Blue Rock Springs, Lake Berryessa and San Francisco), 4 Prime Suspect featurettes (His Name Was Arthur Leigh Allen, Linguistic Analysis, Jeopardy Surface: Geographic Profiling and The Psychology of Aggression: Behavioral Profiling), 2 text-based features (Special Agent Sharon Pagaling-Hagan's Behavioral Profile of the Zødiac and Dr. Kim Rossmo's Geographic Profile of the Zødiac) and the film's theatrical trailer. Audio will be Dolby Digital 5.1 on the DVD version, and Dolby Digital Plus 5.1 on the HD-DVD. All of the video-based special features will be in HD on the HD-DVD version.

Source: The Digital Bits