Apple Computer has instructed its PR company to revoke MacWorld Expo Press Passes distributed to certain online sites [slashdot], reportedly because it considers them "rumor-mills." Blacklisting otherwise positive enthusiast sites simply because they might get overeager and publish details of upcoming products is a mistake for Apple, especially if these sites aren't violating NDA (non-disclosure agreements) or press embargoes. Mostly, these sites feed Mac-enthusiasm and community, providing Apple with free PR and user culture on a daily basis.
It seems to me this is a poor call made by a new Apple PR rep who's simply unfamiliar with enthusiast-reporting in the tech sector. It's simply not as clean, or organized, as mainstream media relations. But it's also a much more intense, vibrant media with a better link to its readership. Unless Apple rescinds this decision, it's only going to be ugly for them.