Erg...I have been out of the loop for the past 48 hrs and missed the boat something fierce on this hasty, misguided business and its equally swift retraction. I like Brian's commentary at Out West Arts here--its a bit dramatic to call Gelb's move "censorship" given Opera News' symbiotic relationship with the Met. The bright lines around conflict and censorship expected of criticism in a regular news outlet don't quite apply.
No, this misfire isn't about crushing one's right to voice one's dissent about the Machine's shenanigans; its indicative of a more insidious trend: the ever-growing dominance of PR logic and its friction with the tacit agreement that more honest dialogue about the arts can only be in the best interest of better art and, especially, better consumers of art. Something like opera criticism exists in print not so much by virtue of its irresistible business model, but, as in the case of Opera News, because opera enthusiasts, critics, and institutional interests have made a space for it where space could be found, and because they believe criticism is a necessary part of the broader artistic enterprise.
But that kind of space doesn't fit very well into the PR paradigm of the world, where message discipline is the paramount concern, and contrary, unpleasant voices are only OK insofar as they are nonthreatening--otherwise, they are risks to be mitigated. This may be a bothersome trend in politics or business, though clearly we don't have much choice in the matter anymore. It sure would be nice, though, if we could keep the hackery to a dull roar in our more genteel pursuits.
Update: Lisa has been all over this, of course, and has a good list of links to coverage...