Note that this is not some new grant of permission to actually use material; rather it just means that a documentarian would not be breaking the DMCA if they extract material from a DVD for a lawful use. Determining a legal use isn't always as simple as it sounds, and it's important that you meet all of these criteria:
1. You must have lawfully acquired a lawfully made DVDAs simple as that sounds, there's a lot of misconceptions about "fair use;" but you can find some material about it on the web .
2. You may only copy short portions of material for a "non-infringing use," either material in the public domain or material to be used under "fair use."
3. You must be making the copy to use in a documentary
4. You must only copy what you need, you cannot copy the entire DVD 
Note that the Copyright Office says they will review the situation again in October 2012.
 Copyright.gov: Rulemaking on Exemptions from Prohibition on Circumvention of Technological Measures that Control Access to Copyrighted Works
 Documentary.org: Documentary Filmmakers Win Exemption from Digital Millennium Copyright Act
 Current.org: Doc-makers get specific about copyright fair use
Win one, Lose one
Meanwhile, the Lens Blog of The New York Times reports on an ongoing issue for photographers and videographers; the increasingly common practice of authorities seeking to smother photography in public places under the blanket of “security.”
lens.blogs.nytimes: ‘Step Away From the Camera!’