Why did the NYTimes hold the NSA story for a year?

Big story out in Newsweek tonight on the NSA scandal and why the NYTimes held the story for a year. Johnathan Alter: (This isn't from some whacked out crazy place. This is Newsweek.)

I learned this week that on December 6, Bush summoned Times publisher Arthur Sulzberger and executive editor Bill Keller to the Oval Office in a futile attempt to talk them out of running the story. The Times will not comment on the meeting, but one can only imagine the president’s desperation.

The problem was not that the disclosures would compromise national security, as Bush claimed at his press conference.....

No, Bush was desperate to keep the Times from running this important story—which the paper had already inexplicably held for a year—because he knew that it would reveal him as a law-breaker. He insists he had “legal authority derived from the Constitution and congressional resolution authorizing force.” But the Constitution explicitly requires the president to obey the law.....

Also, Josh Marshall has an interesting post based on the Rockefeller memo theorizing that this might be a clone of the TIA or some great vacuum which sweeps up and "searches" all emails.