As far as I understand, this NDA is used to make big newspapers publish reviews of the new OS at the same time to make a concentrate PR effort. If every big new

As far as I understand, this NDA is used to make big newspapers publish reviews of the new OS at the same time to make a concentrate PR effort. If every big newspaper was free to review Mavericks, by the time it got out, no one would care about it. Also, early builds always have bugs and shortcomings and those will be discussed in the reviews. Using NDA Apple makes sure that major media sources release info on the latest, most tested version and at the same time to create necessary effect on the readers.