From the NY Times story:
The 600-page report, which the Justice Department has tried to keep secret for four years, provides new evidence about more than two dozen of the most notorious Nazi cases of the last three decades.IMHO, the real question is: Why the secrecy? Tom Lehrer wrote a satirical song about Werner von Braun in the 1960s, after all.
My guess is that it sets a precedent for disclosure of documents relating to Islamist extremist terrorists working for the US government, paid for by the US government, killing Americans and American allies while receiving US government subsidy--which, after 9/11, would be hard to explain to the American people.
Especially since, unlike Nazis, Islamist extremist terrorists haven't been defeated yet...
UPDATE: FOIABlog linked to this item from the Federation of American Scientists:
A side-by-side review of the leaked and the redacted versions compels the conclusion that the Department of Justice exceeded its authority to withhold information from the public, and violated the disclosure requirements of the Freedom of Information Act. “Now that we can compare the redacted document with the complete text of the original report, it is clear that the Justice Department is withholding information without legal justification,” said attorney David Sobel, who represented the National Security Archive in its request for the document. “For an administration — and an Attorney General — supposedly committed to an ‘unprecedented’ level of transparency, this case provides a troubling example of how far the reality is from the rhetoric.”More from the National Security Archive.